MAPAN Journal -34

Abstract for Volume 34, Issue 1, March 2019

A Calibration Method of Portable Coordinate Measuring Arms by using Artifacts
Chang-Hyon Rim, Chol-Min Rim, Jin-Guk Kim, Gang Chen, Jong-Su Pak

Abstract

Portable coordinate measuring arm (PCMA) calibration is an efficient way to enhance PCMA accuracy. Optimal test configurations during PCMA calibration are helpful to reduce measuring points and reduce consumption time for calibration. In this paper, a kinematic calibration approach has been proposed for 5DOF PCMA, in which ASME B89.4.22-2004 standard and a self-made ball bar for volumetric calibration test are employed. First, a kinematic error model of PCMA is established, and the error parameters are identified. Second, data processing is carried out based on data obtained from tests including single-point precision calibration test using chamfered hole seat, effective diameter calibration test using the reference spheres, volumetric and distance displacement calibration test using ball bar, and machine coordinate origin determination test using the base plane and base cylinder. Third, the objective function for the identification of kinematic error parameters is established, and it is solved by using Levenberg–Marquardt algorithm. Finally, the results of calibration test are compared with the ANSI/ASME B89.4-2004 performance test. The experimental results show that the single-point repeatability of the machine is reduced 1.1 times and the distance accuracy is enhanced 1.17 times by data processing.

Keywords

AACMM Kinematic error model Repeatability Measurement accuracy Calibration
Contributions of National Standards on the growth of Barometric Pressure and Vacuum Industries

Ashok Kumar, Vikas N. Thakur, Afaqul Zafer, N. D. Sharma, Sanjay Yadav, D. K. Aswal

Abstract

A rigorous data analysis has been carried out for various barometric pressure transmitters and sensors and vacuum gauges over a period of 8 years; it has been found that a small fraction of pressure and vacuum industries and research institutions from private and government organizations approach to National Metrology Laboratory (NMI), CSIR-NPL, for calibration of their equipment. The observation also pointed out that it might be possible that the traceability chain throughout the country is not properly maintained; especially keeping in view that India is one of the fastest economies in the world.

Keywords

Metrology Traceability Pressure and vacuum metrology Measurement 

Comparative Study on Absorbed Dose Distribution of Potato and Onion in X-ray and Electron Beam System by MCNPX2.6 Code
I. Peivaste, Gh. Alahyarizadeh

Abstract

The absorbed dose distribution and depth dose of X-ray and electron irradiation in a phantom of water, a box of onion and potato powder, and a box of fresh onions and potatoes were calculated by using Monte Carlo N-Particle extended (MCNPX2.6) code. Simulation parameters were extracted from a Rhodotron accelerator at Yazd Radiation Processing Center (YRPC). The estimated absorbed dose distribution and depth dose in the water phantom show the well-distributed absorbed dose of 0.8–1.8 kGy for X-ray. This finding is consistent with the experimental results. However, the dose depth and distribution of electron irradiation are inappropriate. As such, the optimum conditions were obtained for electron irradiation by varying box thickness, beam current and distance between energy source and box surface. Optimum energy and current, box wall thickness, and distance between energy source and box surface were also estimated for onion and potato powders and for fresh onions and potatoes to achieve the appropriate dose distribution and desired depth dose of 1–3 kGy for onion and potato powder and 0.1–1 kGy for fresh onions and potatoes. Therefore, appropriate irradiation processes to powders and fresh materials are X-ray and electron irradiation, respectively.

Keywords

Absorbed dose distribution Depth dose X-ray and electron beam system MCNPX2.6 code 

Removal of Specular Reflection and Cross Talk in Sonar for Precise and Accurate Range Measurements

Ravinder Singh, K. S. Nagla

Abstract

Sonar sensor based range measurement for mobile robot mapping/perception of the complex environment is considered as proficient and low cost technique. Sonar sensor are employ for various applications such as autonomous navigation of mobile robot, underwater navigation and mapping, perception of shape and size of objects, etc. Different configurations are used in the past to mount the sonar sensors on the front/back/side of the mobile robots for the accurate and precise perception of the environment. The fast, precise and consistent sonar occupancy grid mapping is the key requirement for the various mobile robot applications which results in the use of multiple sonar sensors in the form of convex shape sonar rings mounted on mobile robot. Sonar rings provide fast mapping of the environment but, at the cost of low reliability, less precision and inconsistency in the occupancy grid due to specular reflection, false triggering synchronization and cross talk. This paper presents a novel technique for the construction of concave shape sonar rings called C-type arrangement (CTA) of sonar sensors which is derived from the analytical and mathematical study of convex type sonar sensor rings, circle geometry, trigonometry and Sonar sensor model. CTA approach is designed with an objective of examine metrological characteristic of multi sonar rings such as uncertainty, precision and error in range measurement. CTA technique reduce the uncertainties in sonar occupancy grid mapping due to specular reflection and cross talk for the application such as autonomous navigation, path planning, mapping, localization, etc. The proposed technique is experimentally verified in various real world experiments and enhanced results are analyzed both quantitatively and qualitatively that validate the reliability of the CTA technique. The CTA technique enhance the reliability in sonar sensor range measurement for the various robotics task like space exploration, mining, search and rescue operation, underwater surveillance etc.

Keywords

Occupancy grid Sonar sensor specular reflection Mobile robot navigation 

Implementation and Analysis of a Reference Partial Discharge Measurement System

Ahmet Merev, İsmail Karaman

Abstract

Partial discharge (PD) detection is based on the measurement of apparent charge originated from PD in test sample. Since the measurement system configuration affects the PD measuring system response, a PD reference calibrator is the most important part of measuring system for the determination of scale factor in measurement system. In this paper, the design and implementation of reference partial discharge measurement system for the calibration of reference calibrator is presented. The reference pulses to be checked in the implemented measuring system are generated by the reference partial discharge generator or calibrator that is constructed for the characterization of the reference measuring system according to the requirement of IEC 60270. Proper correction for known errors and estimation of uncertainty contributions proved that traceable measurement of partial discharge can be made with an uncertainty of less than 1% in the range of between 2 pC and 1000 pC.

Keywords

Partial discharge Partial discharge measurement Charge measurement Calibration Reference partial discharge calibrator 

Verification of the Main Ratios of the 6010C Automatic Bridge Used for Resistance Measurement

Rasha S. M. Ali, M. Helmy A. Raouf

Abstract

The main ratios of the Measurements International corporation (MI) 6010C automatic resistance bridge have been verified in this paper. The used method for verification is the exchanging method where the two resistors are interchanged, and then the offset error is computed. Then, this method has been evaluated by two other comparison methods for the 1:1 and 1:10 ratios. The expanded uncertainties at the different ratios are also evaluated. The studies on a verification of the mentioned ratios of the MI6010C DCC bridge had been rarely reported. Based on the obtained results, the introduced verification method can be reliably used to verify any MI6010C DCC bridge that serves at any measurement laboratory.

Keywords

Direct current comparators Ratio bridge technique Low-resistance measurements Uncertainty 

Simultaneous Measurements of Ambient NH3 and Its Relationship with Other Trace Gases, PM2.5 and Meteorological Parameters over Delhi, India

Saraswati, M. P. George, S. K. Sharma, T. K. Mandal, R. K. Kotnala

Abstract

In the present study, trace gases (NH3, NOx, CO and SO2), PM2.5 and meteorological parameters were carried out at 5 different monitoring sites [CSIR-National Physical Laboratory, New Delhi and other 4 air quality measurements (AQMS) sites (Anand Vihar, Mandir Marg, Punjabi Bagh and R.K. Puram) of Delhi Pollution Control Committee (DPCC)] of megacity Delhi, India, from January 2013 to December 2015 to estimate the spatio-temporal variation of pollutants over Delhi. The results showed large spatial and seasonal variations in mixing ratios of ambient trace gases and PM2.5 concentration over Delhi. The average mixing ratios of NH3, NO, NO2, CO and SO2 were 53.4 ± 14.9 ppb, 42.0 ± 14.6 ppb, 39.6 ± 13.0 ppb, 1.9 ± 0.4 ppm and 4.3 ± 1.0 ppb, respectively, whereas average concentration of PM2.5 was 136.2 ± 49.6 µg m−3 during the entire study period. All the trace gases and PM2.5 showed maxima during winter season followed by summer and monsoon seasons at all the sites. The 24-h average mixing ratios of the trace gases (NH3, NO, NO2, CO and SO2) and PM2.5 were recorded higher when compared with other sites of the country. The concentration of PM2.5 is breaching the prescribed standard limit of National Ambient Air Quality Standards (NAAQS) of India.

Keywords

Ambient NH3 Trace gases PM2.5 Correlation analysis Sources Meteorology 

Validation of New ITU-R Rain Attenuation Prediction Model over Malaysia Equatorial Region

A. Semire, R. Mohd-Mokhtar, I. A. Akanbi

Abstract

Attenuation due to rainfall is one of the most fundamental constraints on the performance of satellite links above 10 GHz. This work presents the results of rain attenuation measurement using radar data collected from MMD and DIDM, Malaysia. The results were compared with newly improved ITU-R P530-16 and four other selected tropical rain attenuation prediction models. The statistical analysis showed that ITU-R P 530-16 has significantly addressed the problem of rain attenuation underestimation prediction as presented by the older version of the recommendation. Although point accuracy is far-fetched in reality, more improvement is needed on the model so as to address its insufficiency in tropical and equatorial rain attenuation estimation.

Keywords

Radar data Satellite signal Rain attenuation Standard deviation Equatorial region 

Availability Analysis of Industrial Systems Using Markov Process and Generalized Fuzzy Numbers

Neha Singhal, S. P. Sharma

Abstract

The knowledge about the availability of the component states of a system plays a crucial role in studying the assessment techniques of availability of the system. However, component states are often unknown or uncertain, especially during the early stages of the development of new systems. In such cases, it is important to understand how uncertainties will affect system reliability assessment. In the present article, a strategy for the assessment of dependability investigation of industrial systems has been contemplated in more summed up way. In this methodology, reliability/availability has been computed through Markov process. Uncertainty in data has been dealt with generalized fuzzy numbers. Availability of system in transient as well as steady state has been examined in this article. Results have been computed and then compared by performing different arithmetic operations’ approaches. For application perspective of proposed approach, a butter-oil processing plant has been considered. Impact of different arithmetic approaches in the methodology is reflected by numerical calculations and is depicted through the graphs.

Keywords

Availability generalized fuzzy number Markov process Differential equations 

Senarmont Compensator Method Using Inexact λ/4 Plate

A. Mahmoud, N. N. Nagib, M. S. Bahrawi

Abstract

Phase plates are widely used in optical polarization systems to change the state of polarization of a polarized beam to any required state or to determine the state of polarization. The simplest known method for calibrating a phase plate is the Senarmont method. The problem of this method is that the compensating plate must be of exact quarterwave retardance at the working wavelength which is very difficult to obtain. Another disadvantage of the method is that the calibration process can be performed only at this wavelength. In this paper, we present a procedure for accurate calibration of a phase plate using inexact compensating λ/4 plate. The method is applicable at any wavelength so long as the retardance of the compensator is less than π.

Keywords

Phase plates Optical polarization Senarmont method Retardance 

Relevance of Dimensional Metrology in Manufacturing Industries

Girija Moona, Mukesh Jewariya, Rina Sharma

Abstract

Measurement is the most fundamental concept of science and technology that leads to innovations. As per the general concept, measurement is just a tool to determine quantity, whereas in reality, measurement is a fundamental aspect to control and improve various parameters associated with different technical affairs. In the present scenario, the manufacturing of extremely complexed products needs high quality control to meet the design specifications, desired functional outcomes and norm compliances. In industrial manufacturing, the main objective is quality control by eliminating errors and improving the process by precision dimensional measurement methods/devices and following standards and recommended guidelines. Precision and traceable dimensional metrology caters the industry needs ranging from macro-engineering applications to nanotechnology and helps in supporting the objective “make it right in the first time” and hence has become an inextricable part of the advance manufacturing industry.

Keywords

Measurement Precision Nanometrology Traceability Uncertainty Standards 

Simulation Analysis of Outboard Gas Status for Spacecraft Gas Leakage In-Orbit

Lian Chen, Ya-li Li, Yong-jun Cheng, Meng Dong, Dong-hua Sun, Lan Zhao, Wen-jun Sun

Abstract

Due to high vacuum environment of spacecraft orbiting and complex external surface structure of spacecraft cabin, outboard leak detection of spacecraft in-orbit cannot directly adopt existing mature technology. In this article, outboard gas status of spacecraft leakage in-orbit is simulated through computational mechanics and Monte Carlo simulation methods. The simulation results show that complex external surface structure of spacecraft cabin, especially external thermal control layers composed of multilayer insulation material, obviously blocks leakage gas into astrospace and reduce detection sensitivity of outboard leak detection methods. This simulation process and results can provide analyze method and theoretical data for detection scheme design and testing instrument selection of outboard leak detection in the future.

Keywords

Simulation analysis Gas leakage Outboard leak detection In-orbit Spacecraft 

Investigations on Metaheuristic Algorithm for Designing Adaptive PID Controller for Continuous Stirred Tank Reactor

Harsh Goud, Pankaj Swarnkar

Abstract

An integral part of industrial processes is the Continuous Stirred Tank Reactor (CSTR) whose dynamic characteristics are highly nonlinear causing the reactor to deviate from its set temperature point. For its efficient operation, specific parameters of the CSTR are required to be controlled. Hence, this paper presents designing of the Proportional-Integral-Derivative (PID) controller using conventional and metaheuristic methods for the temperature control of the CSTR. The conventional controller is tuned with Ziegler Nichols (Z-N) method. Global search population-based metaheuristic methods like Artificial Bee Colony (ABC), Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) have been implemented to optimize the adaptive controller parameters, and a comparative analysis is done taking the step response into consideration. The CSTR system is simulated by the proposed controller which improves the robustness, behaviour and tracking of the system. The simulation results present substantial enhancement of the time response parameters, i.e. settling time, rise time, peak overshoot, mean square error and integral time absolute error. Studies showed that the proposed adaptive methods with metaheuristic algorithms are fast and efficient in error reduction. Here, ABC irrespective of other optimization methods suitably optimized the controller parameters.

Keywords

Continuous Stirred Tank Reactor (CSTR) PID controller Artificial Bee Colony (ABC) Genetic Algorithm (GA)

Artificial Neural Network Technique for Statistical Downscaling of Global Climate Model

Rajashekhar S. Laddimath, Nagraj S. Patil

Abstract

The nineteenth century, an era of industrialization, witnessed huge utilization of natural resources extensively for the construction activities besides emission of nitrous oxide and methane (greenhouse gases). Rises in the GHG play an important role in the impact on climate change. Rapid and dynamic changes of earth climate have affected human life physically, psychologically, and emotionally. General circulation models (GCMs) are the numerical models developed using a set of linear and nonlinear partial differential equations. Climate and weather forecasting reliability can be possible with the use of GCMs. Statistical downscaling is popular among the research community on an account of building a strong and accurate relationship between GCM and local level information. Among the wide range of regression models, artificial neural network (ANN), a multilinear regression method, is the most popular approach, which works on the basis of transfer function statistically relating predictors and predictands. ANN is developed particularly to address present requirements in global environmental change research and necessitate for more detailed temporal and spatial information from GCM. For the present work, CanCM4 at grid size 2.8° × 2.8° developed by Canadian Centre for Climate Modelling and Analysis has been chosen based on the skill score. It gives historical data from 1971 to 2005 as well as the data consisted of future simulations by emission scenarios RCP4.5 from 2006 to 2035. The data were extracted to cover the entire Bhima basin with nine grid points. Observed meteorological data provided by Indian Meteorological Department (IMD) are used for calibration and validation of ANN model. Karl Pearson’s coefficient is taken as guideline to test the sensitiveness of predictors. To evaluate the performance of downscaling model, Nash–Sutcliffe coefficient and root-mean-square error performance indices have been adopted. With the good predictor and predictand correlation, the work moves on to investigate the application of the transfer function in the form of statistical downscaling. The downscaled results can be applied to watershed management such as flood and drought management studies of the Bhima basin.

Keywords

Climate change Statistical downscaling GCMs ANN Predictors and predictands 

Uncertainty Estimation in PM10 Mass Measurements

Jyoti Pokhariyal, Anubha Mandal, Shankar G. Aggarwal

Abstract

Mass measurements of particles in the atmosphere are important for regulatory and scientific purposes. In nearly all of the countries, particulates ≤ 10 µm in aerodynamic size (PM10) are one of the most significant parameters of National Ambient Air Quality Standards (NAAQS). In India, as given in NAAQS, the PM10 regulatory limit is 60 µg m−3 which is based on the annual mean weight of samples (minimum 104) annually at a specific site taken for two/three days in a week for 24 h. In this paper, the components of uncertainty involved in the filter-based sampling of PM10 along with the gravimetric determination of mass have been calculated. As per the EPA guidelines, PM10 mass was monitored for a year at NPL (National Physical Laboratory), New Delhi from January 2014 to January 2015. The 24-h time-weighted mean mass concentration (n = 104) for one-year measurement varied from 32.5 to 480.2 µg m−3.During the study, high mass loading was observed in the month of December to February. In general, the flow rate of the sampling has been reported to be major uncertainty component in size-segregated PM sampling. In this work, the flow rate of the sampling (90.4%) and charge effect of the filter (6.7%) had the major contribution in the total uncertainty budget of PM10 mass measurement. Rest of the uncertainty components, e.g., balances (0.39%) and conditioning of filter (2.39%), had the least contribution.

Keywords

PM10 NAAQS Measurement uncertainty PM 

Abstract for Volume 34, Issue 2, June 2019

 

Monitoring of the Drift of the Pt–Ir Kilogram Prototypes of KRISS, Traceable to BIPM As-Maintained Mass Unit

 

Lee, J. W. Chung

Abstract

The Bureau International des Poids et Mesures (BIPM) announced recently that its as-maintained mass unit had been changed as the result of Extraordinary Calibration. Following that amendment, the mass change of the national prototype of the kilogram (NPK) of Korea, No. 72, did not show the positive rate of drift shown in other Pt–Ir prototypes. Before the amendment, the drift rate was incorrectly evaluated to have a positive slope as a time evolution. However, we have collected measurement data for two other prototypes, Nos. 39 and 84, for about 15 years in an annual comparison with the NPK. Our periodic monitoring found drifts of a few micrograms in transit as it crossed international borders. Inspired by the new amendment of the reference prototype, our analysis of linear and exponential modeling with the least square method indicated that the modeling results of the mass change of prototypes Nos. 39 and 84 were very similar to those of earlier studies, regardless of the way we assign reference values. Prototype No. 39 notably showed unexpected behavior in the third verification: It recovered to about 1.0 μg/year, the normal rate of mass change. Different from our intuition, the mass drift of the prototype did not seem to be heavily influenced by a physically poor surface. However, in assigning the reference value in an interpolated manner, this study gives the lowest uncertainty of fitting parameters considered as evidence to prove the validity of the last evolution of the BIPM as-maintained mass unit.

Keywords

Prototype of the kilogram Mass drifts Mass comparison 

 

Calibration of Endoscopic Systems Coupled to a Camera and a Structured Light Source

 

Octavio Icasio-Hernández, Juan B. Hurtado-Ramos, José-Joel Gonzalez-Barbosa

Abstract

We propose a calibration method for measuring accurate 3D coordinates inside hollow parts using an endoscopic system consisting of a fiberscope, a camera coupled to the eyepiece of the fiberscope, and a power LED adjusted to the front end of the fiberscope’s bundle. The power LED was adapted to generate a structured light plane (SLP). The calibration method reduces the uncertainty of intrinsic camera parameters by using a traceable printed pattern fixed to a glass flat. The extrinsic camera parameters or SLP position and orientation (POSE) on the camera system are assessed with the projection of the SLP on printed flats. Part of the SLP POSE is the SLP to camera distance, which is measured and adjusted using calibrated ring gauges as follows: we projected the SLP on the inner surface of a calibrated ring gauge, then we obtained the parameters of the circumference (i.e. its diameter) and compared it to the calibrated parameters. Next, we adjusted the distance of interest until measured and calibrated ring parameters were close enough. Using this calibration method, we measured the diameter of several ring gauges and a break master cylinder, finding an average error between ±0.03±0.03 mm with a diameter uncertainty around 0.055 mm.

Keywords

Endoscopic systems Camera calibration structured light Uncertainty Ring gauges 

 

A Portable Online Current Monitoring System with High Precision

 

Zhenhua Li, Chunyan Li

Abstract

The monitoring of current is great significance to evaluate the running state of electrical equipments. In this paper, a portable high-precision online current detection system is presented, and a current sensor is designed which can be opened-closed conveniently. The current sensors have the same frame structure and size, but the number of turns is different. Coils with fewer turns are used to measure the large current, and coils with more turns are used to measure the weak current. By the cooperation of two coils, the accurate measurement of current in a large dynamic range can be achieved and has the advantages of easy installation and small size. In order to improve the accuracy, an improved digital integration algorithm is proposed. The results show that the error of the system is not more than 0.7% when the current ranges from 0 to 1 A, and the error is not more than 0.21% when the current is between 1 and 100 A.

Keywords

Current monitoring Fault diagnosis Current sensor Digital integration 

 

Simplified and Accelerated Method of Led Lamp Useful Life Estimation

 

Vytautas Dumbrava, Darijus Pagodinas, Vytautas Knyva, Irmantas Kupciunas, Gedeiminas Cincikas, Alius Noreika, Lauryna Siaudinyte

Abstract

LED lamps have experienced growth of usage in artificial lighting because of their high luminous efficiency, long lifetime and resistance to mechanical stresses. Many new manufacturers are starting to produce such lamps, and a part of them do not have enough experience in this particular field. This leads to cheap products that do not meet the product-specific requirements. Due to this reason, a study was initiated in order to analyze standards governing LED light sources, and the simplified and accelerated method for evaluation of lumen maintenance life of LED lamps was proposed. In this paper, the initial results of lamp temperature parameters, the AC/DC converter efficiency analysis and the experimental results of measurement and calculation of lumen maintenance life L70 by applying the proposed technique are discussed.

Keywords

LED lamp Photometric parameters Useful time Lumen maintenance life 

 

FEA-Based Design Studies for Development of Diaphragm Force Transducers

 

Rajesh Kumar, Shanay Rab, B. D. Pant, S. Maji, R. S. Mishra

Abstract

This paper discussed the finite element analysis (FEA)-based design considerations and its role in finding optimum location of sensing element in diaphragm-based force transducers. The design studies of two diaphragms made of two different materials steel (EN 24) and silicon are discussed as per the analytical expressions available and further validated using FEA for values of deflection, stress and strain of the spring element with appropriate location for fixing of strain gauges so as to get the optimum output in electrical units in mV/V against the applied force. The proposed analytical study in conjunction with finite element analysis shall be indispensable in design and development of diaphragm-based force traducers of optimum electrical output for different industrial applications and also could be used as force transfer standard to disseminate the measurement traceability chain in force measurements throughout the country. The metrological investigation revealed that the measurement uncertainty is 0.06% for steel force transducer and 0.22% for silicon diaphragm force transducer.

Keywords

Strain gauges FEA Stress Strain Deflection Traceability Transducer 

 

Utilizing Features Extracted from Registered 60Co Gamma-Ray Spectrum in One Detector as Inputs of Artificial Neural Network for Independent Flow Regime Void Fraction Prediction

 

H. Roshani, E. Nazemi, F. Shama

Abstract

In this paper, we demonstrate that void fraction could be predicted independent of type of flow regime in two-phase flows using 60Co source and one scintillator NaI detector. For this purpose, firstly three features (Feature No. 1: counts under Compton continuum; Feature No. 2: counts under full energy peak of 1173 keV; Feature No. 3: counts under full energy peak of 1333 keV) were extracted from registered gamma-ray spectrum in detector. Secondly, these three features were utilized as the inputs of artificial neural network model of multilayer perceptron (MLP) in order to achieve the best structure for predicting the void fraction. In each structure, void fraction was considered constantly as the output of MLP network. Using the optimum MLP network structure, void fraction was predicted independent of type of flow regime in gas–liquid two-phase flow with MRE of less than 2.5%. Although obtained error using one detector for predicting the void fraction is more than when two or more detectors are utilized, using fewer detectors has advantages such as making the detection system simpler and reducing economical expenses.

Keywords

60Co source Multilayer perceptron Two-phase flow Regime independent Feature extraction 

 

Effect of Illumination Systems on Statistical Texture Parameters Based Clustering and Discrimination of Machined Surfaces Using Machine Vision

 

Ketaki N. Joshi, Bhushan T. Patil

Abstract

Inspection of surface quality using machine vision is based on the principle of surface characterization using texture parameters deduced from intensity values of images captured by the system. Illumination system plays significant role in deciding the performance and robustness of machine vision by controlling quality of image acquisition. This paper presents an experimental study of the effect of various illumination systems on image acquisition. Images of flat machined surfaces under five different illumination setups: ambient light, dark field, partial bright field with spotlight, partial bright field with tubelight and partial bright field with diffuse surface light; are grouped into three surface classes based on first and second order statistical texture parameters. The result showed that partial bright field with diffuse surface light provides maximum performance during image acquisition providing highest clustering accuracy. The images under this optimum setup are further analyzed using multiple discriminant analysis for determining the parameters significantly contributing to discrimination. The results showed that average height departure, root mean square, maximum peak to valley, skewness based on line samples; maximum peak to valley, skewness, kurtosis for surface and gray level co-occurrence matrix based contrast, correlation, energy, homogeneity effectively contributed to characterization of texture for discrimination.

Keywords

Machine vision Illumination system Texture analysis Cluster analysis Discriminant analysis 

 

Proficiency Investigation of Torque Tools Calibration as a National Demand

 

M. Khaled, Seif M. Osman

Abstract

The current paper represents a round loop for calibration of torque tools organized by NIS. These measurements are aimed to evaluate the performance of torque tools calibration laboratories in Egypt in the range from 200 N m up to 1000 N m in both clockwise and anticlockwise directions. Results are evaluated using En-value method and Z-score method based on the weighted means and the corresponding uncertainties. The outlier test and consistency test were performed on the measurements before applying the Z-score test. The Z-score evaluation shows that participants’ results are consistent specifically in the range from 400 N m up to 1000 N m. Further comparison with lower capacity artifact is recommended in the lower torque range.

Keywords

Torque Calibration Proficiency test En-value Z-score 

 

Seasonal and Spatial Variation of Particulate Aerosols and Carbonaceous Species in PM2.5 in the Periphery of Chandigarh, India

 

Sandeep Garg, Deepika Thakur, Rai Singh, Anita Rajor, Amit Dhir

Abstract

Present study highlights the seasonal and spatial variation of particulate aerosols (PM10 and PM2.5) and carbonaceous species (organic tarry matter, organic and elemental carbon) in PM2.5. The ambient air samples for particulate aerosols were collected from tricity of Chandigarh, Mohali and Panchkula in India during summer (April’15–May’15) and winter (December’15–January’16). The mass levels of particulate aerosols and carbonaceous species show significant variation both seasonally and spatially. Average mass levels reported as higher in winter than summer were attributed to stagnant atmospheric and poor dispersion conditions. The mass levels were also found to be higher in industrial area as compared to residential and commercial areas. Average mass levels varying from 107.6 to 137.8 µg m−3 for PM10 and 46.6–59.5 µg m−3 for PM2.5 during the study period indicate alarming situation of particulate aerosols in this tricity. Carbonaceous species contributing as 42.5–47.5% OTM, 25.4–29.9% OC and 3.4–4.7% EC in PM2.5 indicate larger in fraction at all sites during both summer and winter.

Keywords

Elemental carbon Fine particulate matter Organic carbon Organic tarry matter Seasonal and temporal variation 

 

Current Transformer Accuracy Improvement by Digital Compensation Technique

 

Makarand Sudhakar Ballal, Manish Ganesh Wath

Abstract

Measurement current transformers (CTs) are extensively used for measurement of energy by power distribution utilities. In this paper, current transformer error compensation unit (CTECU) is developed which is specially intended for providing compensation to all types of measurement CTs. The proposed CTECU is based on determination and application of correction coefficients, which are computed by the ratio and phase angle errors data. Analytical foundation is effectively expressed along with the development of CT error compensation algorithm. CTECU is implemented online in laboratory on 1.0 class and 0.5 class of CTs. The experimental performance is found satisfactory under various operating conditions. The novelty of the proposed algorithm is that it is possible to make conversion of CTs from one class to another class.

Keywords

Current transformer error compensation unit (CTECU) Ratio error Phase angle error Digital compensation technique 

 

Sonar Sensor Model for the Precision Measurement to Generate Robust Occupancy Grid Map

 

Ravinder Singh, Kuldeep Singh Nagla

Abstract

Precise measurement of the parameters such as position and angular coordinates, distance travelled, and velocity and acceleration of an autonomous mobile robot in occupancy grid map is an active area of research. The stated parameters rely on the probability values stored in the grid cells of the occupancy grid. Occupancy grid mapping is a proficient paradigm in the field of mobile robotics for modeling the environment by receiving the sensory information from range sensors. The objective of this study is to develop novel approach—adaptive sonar model (ASM)—for the generation of robust occupancy grid by reducing the effect of inconsistency in the grid cells probabilities of the occupancy as a consequence of long-range measurement. The results acquired with the implementation of the ASM techniques are compared with the conventional sonar sensor model which reveals 20% reduction in the uncertainty in the occupancy grid map generated due to long-range measurement.

Keywords

Sonar sensor model Occupancy grid mapping Probabilistic model 

 

Intra- and Interlaboratory Approach for Certification of Reference Materials for Assuring Quality of Low-Alloy Steel Measurement Results

 

Abstract

Certified reference materials are versatile tools to support quality, correctness and credibility of measurement results. They are used to provide the traceability of the measurement results to the SI unit. In the present work, seven low-alloy steel reference materials were developed by the National Institute of Standards, Egypt. Homogeneity of the developed reference materials (RMs) was studied by X-ray fluorescence spectrometer (XRF) and atomic emission spectrometer, and the results proved that the produced RMs were homogeneous enough for establishing traceability of measurement results and internal and external quality control schemes. Characterization of reference materials composition was performed by four independent analytical methods: gravimetry, XRF, optical emission and atomic absorption spectrometry in different laboratories. The assigned values of the mass fractions of the various elements of the alloys and their associated uncertainty were calculated by the weighted mean approach.

Keywords

Low-alloy steel Homogeneity Reference materials Traceability Uncertainty 

 

New Method for Measurement of AC Voltages above 1 V Using TVC and Voltage Divider

 

Rasha S. M. Ali, M. Helmy A. Raouf

Abstract

In this paper, a new method is introduced for AC voltage ranges that are higher than 1 V by using the thermal converters. It can be used in laboratories in case of unavailability of the whole ranges of multiplier range resistors set. The introduced method depends on dividing the AC voltage of the unit under test to 1 V by using AC voltage divider. The divided AC voltage is then measured using 1 V thermal converter. The measured AC voltages are 10 V and 30 V at different frequencies. The expanded uncertainty is evaluated for the measurement results. The presented method is evaluated by comparing its obtained results and the results obtained by using the conventional thermal voltage converter, which consists of multiplier resistors, with the actual values of the AC voltages. The comparison proves that the new method is reliable and dependable for accurate measurements of AC voltages.

Keywords

AC voltage measurement Thermal converter Thermal voltage converter Multiplier range resistor AC voltage divider Uncertainty 

 

Enhanced Ozone Production in Ambient Air at Patiala Semi-Urban Site During Crop Residue Burning Events

 

Madhvi Rana, Susheel K. Mittal, Gufran Beig

Abstract

The continuous in situ measurements of criteria pollutants (O3, CO and NOx) and meteorological variables were done at a semi-urban site (Patiala) of North-West Indo-Gangetic Plains (NW-IGP) for the years 2014 and 2015. The influence of meteorology on the levels of criteria pollutants was investigated on daily, monthly, seasonal and diurnal basis. The average rate of increase in O3, calculated to be 1.1 ppb h−1 and pollution index (daily O3 max/O3 min ratio), values (10.2) indicates remarkable ozone pollution. Ozone is negatively correlated (represented as r value) with its precursor gases CO (− 0.28) and NOx (− 0.32), as they get consumed in the photochemical production of ozone. The impact of meteorology on ozone production was positively correlated with SR (0.63), AT (0.49), MT (0.59) and WS (0.23) and negatively correlated with RH (− 0.83). Pre-, during and post-biomass burning periods were determined using Terra-MODIS images over the study area. Enhanced levels of ozone were recorded as 20 ppb and 15 ppb during daytime, respectively, for rice and wheat crop seasons, and 12 ppb during nighttime for both seasons. Ozone exceedance of 24 h national standard occurred on 50% and 8% of the sampling periods during wheat and rice crop residue burning, respectively. Ozone generation with its precursor gases was analyzed quantitatively.

Keywords

Ambient air quality Meteorology Surface ozone Crop residue burning N.W. Indo-Gangetic Plain Pearson correlation 

 

Experimental and Theoretical Study of the Measured Wavelength of Laser Light Using Mach–Zehnder interferometer

 

Hameed Naser, Haider Mohammed Shanshool, Saaid Flaih Hassan, Amer B. Dheyab

Abstract

In this research, the experimental and theoretical studies to measure the wavelength of laser light by Mach–Zehnder interferometer were conducted. Then, the results were compared with Zemax software. The fringes have been obtained both as shining and dark. The wavelength of laser light and the diameter of fringes were calculated by the optical system. The calculation relies on the measure of the airy disk diameter, whose approximation is directly proportional to the wavelength of the laser source; and to the space between the aperture and the image plane. However, the calculation is reciprocally proportional to the diameter of the aperture. Then, the results were compared with Zemax software, where the ratio of error is very small.

Keywords

Mach–Zehnder Diode laser Interference fringes Ray-tracing software 

Abstract for Volume 34, Issue 3, September 2019 (Special Issue on Uncertainty Evaluation by Monte Carlo Method)

 

Uncertainty Evaluation by Monte Carlo Method

 

Rachakonda, V. Ramnath, V. S. Pandey

Abstract

Measurement uncertainty is a parameter that is used to characterize the dispersion of the values attributed to a measurand. There are multiple definitions of measurement uncertainty that were adopted by various international working groups. The differences in definitions are small and of interest mainly to experts in the field. The methods used to estimate the uncertainty, however, were found to vary widely between different fields of metrology, even among national metrology institutes. The problem was studied, and a set of guidelines were published in the early 1980s. To implement the guidelines and harmonize the methods to estimate uncertainty, a guide with specific steps and numerous examples was developed and published as the Guide to the Expression of Uncertainty in Measurement (GUM) in 1995. The GUM is published by the Joint Committee for Guides in Metrology (JCGM), which is a group comprised of eight other international organizations. There have been periodic updates and extensions to the GUM, developed by JCGM, which included other valid methods to estimate uncertainty, and it is a continuing international effort.

 

Monte Carlo Simulation in Uncertainty Evaluation: Strategy, Implications and Future Prospects

 

Garg, S. Yadav, D. K. Aswal

Abstract

Monte Carlo simulation (MCS) is an approach based on the propagation of the full probability distributions. It was introduced by the Joint Committee for Guides in Metrology (JCGM) in the supplement I-JCGM 101:2008. It is used to resolve the problem of calculating measurement uncertainties of complex measurands through simulation of random variables. Further, supplement II on “Extension to any number of output quantities” was published in 2011 and supplement III on “Modelling” is under publication. These supplements cover broader range of measurement issues which are not handled using law of propagation of uncertainty (LPU) alone and provide an alternative method to the conventional LPU approach. The MCS method plays a vital role in cases, where the linearization of the model does not provide enough depiction, or the probability density function of the output quantity deviates considerably from the Gaussian distribution. The SWOT analysis describes the strengths, weaknesses, opportunities and threats associated with the use of MCS in the measurement uncertainty evaluation and is addressed in this paper. The paper also summarizes the implications and prospects associated with the use of MCS in uncertainty evaluation for wide usage in solving problems in physical, biological and engineering sciences.

Keywords

Measurement uncertainty Law of propagation of uncertainty (LPU) Monte Carlo simulation (MCS) 

 

Comparison of Monte Carlo Simulation, Least Square Fitting and Calibration Factor Methods for the Evaluation of Measurement Uncertainty Using Direct Pressure Indicating Devices

 

Shanay Rab, Sanjay Yadav, Afaqul Zafer, Abid Haleem, P. K. Dubey, Jasveer Singh, Rahul Kumar, Raman Sharma, Lalit Kumar

Abstract

At present, several measuring instruments are commercially available in the market for accurate and precise pressure measurements. In case of electromechanical type pressure sensors, the evaluation of measurement uncertainty is always a tedious task for researchers due to lack of availability of the suitable and well-defined mathematical model. In order to harmonize the method of evaluation of measurement uncertainty associated with measuring instruments, “The Guide to the Expression of Uncertainty in measurement,” published by International Standard Organization, is a major directional guide which is equally important in pressure metrology. The present paper describes the various uncertainty propagation models developed for the evaluation of measurement uncertainty associated with direct pressure indicating devices (DPIDs). A detailed comparative study is presented while using Monte Carlo simulation, least square fitting and calibration factor methods for the evaluation of measurement uncertainty using a DPID. In order to judge the feasibility and practical applicability of these contemporary methods, it is demonstrated through an example of a case study on the results thus obtained on a DPID that results using three different approaches are in excellent agreement and quite comparable.

Keywords

Accuracy Calibration Electromechanical Precision Sensor Uncertainty 

 

 

Measurement Uncertainty Evaluation in Vickers Hardness Scale Using Law of Propagation of Uncertainty and Monte Carlo Simulation

 

Indu Elizabeth, Rajesh Kumar, Naveen Garg, Mohammed Asif, R. M. Manikandan, Girish, S. S. K. Titus

Abstract

The Monte Carlo simulation (MCS) method for uncertainty evaluation of measurement results has gained popularity as an alternative to the method based on law of propagation of uncertainty (LPU) ever since the recommendation by JCGM through supplement JCGM 101:2008. In this paper, efforts have been made to compute the uncertainty in measurement of hardness in the Vickers hardness scale using MCS and LPU method. Three different hardness blocks of different hardness scales, namely HV1, HV10 and HV30, have been calibrated following the standard procedure in the primary Vickers hardness machine established in CSIR-National Physical Laboratory. The mean hardness values and the associated measurement uncertainty of the hardness blocks are computed using LPU and MCS methods. A comparison of the results obtained through LPU and MCS methods has been carried out. It is observed that there is a good agreement between findings from both the methods adopted; hence confirming that MCS method can be employed in the various fields of hardness metrology for evaluation of measurement uncertainty.

Keywords

Vickers hardness Monte Carlo Uncertainty Metrology 

 

Measurement Uncertainty Evaluation Using Monte Carlo Simulation for Newly Established Line Scale Calibration Facility at CSIR-NPLI

 

Girija Moona, Vinod Kumar, Mukesh Jewariya, Rina Sharma, Harish Kumar

Abstract

High-precision line scales are probably the most common physical standards for length measurements. They are used as reference standards, transfer standards, direct length measurement devices and ordinary measures for adjustments in length measuring machines etc. Hence, in the current scenario, a robust and reliable line scale calibration infrastructure with high precision and flexibility is of indispensable need. Keeping this in view, an improved calibration facility for line scales, ranging from 300 to 1000 mm, has been established at CSIR-NPL India by combining coordinate measuring machines, vision metrology and displacement measuring laser interferometer. The present article describes line scale (400 mm) calibration setup, measurement procedure and measurement uncertainty evaluation. Here measurement uncertainty evaluation is carried out by using two different approaches, law of propagation of uncertainties (LPU/GUM) and Monte Carlo simulation. The measured mean values and expanded uncertainties obtained by using the above two approaches are found to be in good agreement.

Keywords

Line scale Calibration CMM Vision metrology Laser interferometer Measurement uncertainty 

 

Analysis of the Influence of Water-Vapor Correction Term on the Measurement Uncertainty of Wind Speed

 

Mingming Wei, Yang Zeng, Li Zou, Chunhua Wen, Xiaogang Liu, Changchun Li, Shan Xu

Abstract

In order to explore the influence of water-vapor correction term on wind speed uncertainty, the actual measured value of wind speed by pitot tube is the research object, Firstly, the uncertainty value of the wind speed value obtained by the simplified model (discarding the water-vapor correction term) is evaluated by GUM method. Then, the MCM evaluates the uncertainty of the wind speed value obtained from the original model (including the water-vapor correction term). Finally, two kinds of the evaluation results obtained by the method are compared in the form of probability distribution graphics, and the numerical analysis is carried out. After the water-vapor correction item is discarded, the fluctuation degree and dispersion degree of the measurement result will be reduced, and the degree of reduction is 1.0988% and 1.0929%, respectively. The degree of volatility is about 25.8513% of the degree of dispersion. The degree of influence on the volatility and dispersion of the measurement result is about 0.2305% and 0.8987% of the measured value of wind speed. In the application, for the occasion of pursuing the accuracy of measured value of wind speed, it is recommended to use the original model to measure the real-time wind speed. For the occasion of the stability of the wind speed measurement result, the GUM method can be used to evaluate the uncertainty of the simplified model.

Keywords

Metrology Uncertainty Wind speed MCM GUM

 

Comparison of MCM and GUM Method for Evaluating Measurement Uncertainty of Wind Speed by Pitot tube

 

Mingming Wei, Yang Zeng, Chunhua Wen, Xiaogang Liu, Changchun Li, Shan Xu

Abstract

“The Guide to the Expression of Uncertainty in Measurement” (GUM) method has many disadvantages when evaluating the uncertainty of wind speed measured by pitot tube, and the “Monte Carlo method” (MCM) is put forward to evaluate the uncertainty of wind speed. The measured quantity value of wind speed by the S-shaped pitot tube is the research object, and the uncertainty is evaluated by GUM and MCM, respectively, and the simulation test is carried out. GUM has errors due to its adoption of approximate linear model. MCM adopts real simulation strategy and has higher credibility than the GUM method, so the GUM method can be validated by the MCM method. When the partial input quantity is changed into triangular distribution, uniform distribution and arcsine distribution, the GUM method is found to be inapplicable. In the evaluation of MCM method, the complex calculation of sensitivity coefficient is avoided, and some uncertainty with small influencing quantity is not needed to be discarded. The evaluation result is more complete. Through comparing the uncertainty evaluation results of MCM before and after the water vapor correction term is discarded, the influence of the water vapor correction term is quantified. Therefore, compared with the GUM method, the MCM method has more advantages when wind speed is measured by Pitot tube.

Keywords

Metrology Uncertainty Wind speed MCM GUM 

 

Measurement Uncertainty in Microphone Free-Field Comparison Calibrations

 

Garg, P. Surendran, M. P. Dhanya, A. T. Chandran, M. Asif, M. Singh

Abstract

The present study demonstrates the use of a transportable anechoic chamber for conducting microphone free-field calibrations with lowest levels of uncertainty. A dedicated transportable anechoic chamber (make SPEKTRA, Germany) of internal volume of 2 m3 completely lined with wedge-shaped absorbers is utilized for free-field calibrations in the frequency range of 125 Hz–20 kHz using the substitution method as per the IEC 61094-8 standard. The study has identified the usable working space inside a free-field chamber using the inverse-square pressure law, and the deviations from the inverse-square law of the free-field chamber are quantified. The measurement uncertainty of ± 0.36–0.52 dB (k = 2, 95% confidence level) is evaluated in the frequency range of 125 Hz–20 kHz and is validated in a bilateral comparison. The application of Monte Carlo simulation approach in the evaluation of measurement uncertainty in microphone free-field calibrations is also demonstrated.

Keywords

Microphone free-field calibration Monte Carlo simulation (MCS) Law of propagation of uncertainty (LPU) 

 

Evaluation of Uncertainty in the Effective Area and Distortion Coefficients of Air Piston Gauge Using Monte Carlo Method

 

Vikas N. Thakur, Sanjay Yadav, Ashok Kumar

Abstract

The fixed number of trials in the Monte Carlo method (FMCM) has been employed for the evaluation of effective area along with their associated uncertainties and distortion coefficients of piston–cylinder (pc) assembly of the air piston gauge with varying pressures ranging from 6.5 to 360 kPa. The FMCM uncertainty values are compared with the conventional method, i.e., the law of propagation of uncertainty in the experimental range 20–120 kPa using our primary pressure standard, i.e., ultrasonic interferometer manometer. It is observed that the relative uncertainty of the effective area using FMCM (~ 9.5 ppm) is lesser than that of the experimental value (~ 9.7 ppm) using the same parameters responsible for uncertainty measurement which leads to the quality enhancement in the measurement of pressure.

Keywords

Monte Carlo method Air piston gauge Pressure metrology Uncertainty 

 

Uncertainty Analysis of Distortion Coefficient of Piston Gauge Using Monte Carlo Method

 

Jasveer Singh, L. A. Kumaraswamidhas, Kapil Kaushik, Neha Bura, Nita Dilawar Sharma

Abstract

Uncertainty quantification is the integral part of any measurement and metrological activity. Apart from the conventional method of uncertainty estimations, Monte Carlo method is increasingly being applied for such estimations. In the present work, the Monte Carlo simulation is applied to evaluate the measurement uncertainty in distortion coefficient of one of the secondary pressure standards. In addition, the uncertainty is also estimated by taking the various correlation coefficients into account. The results obtained from these Monte Carlo calculations are compared with the experimental results, and the uncertainty obtained from the law of propagation method is validated by comparison with the Monte Carlo simulation.

Keywords

Distortion coefficient Monte Carlo method Measurement uncertainty 

 

Analysis and Comparison of Hyper-Ellipsoidal and Smallest Coverage Regions for Multivariate Monte Carlo Measurement Uncertainty Analysis Simulation Datasets

 

Vishal Ramnath

Abstract

Traditionally metrology systems have been analysed for measurement uncertainties in terms of the frequency statistics-based Guide to the Uncertainty in Measurement (GUM); however, a key challenge in the application of the GUM has been in terms of its inherent limitations and internal inconsistencies with Type A and Type B uncertainties in adequately and accurately determining appropriate coverage intervals and regions for measurement uncertainty results. Subsequently in order to address these particular issues the Bayesian statistical-based GUM supplements for univariate and multivariate models were developed that supersede the original GUM and which resolve these challenges. In this paper, a GUM supplement 2 uncertainty analysis for a multivariate oil pressure balance model is numerically implemented using an experimental dataset, and then the multivariate Monte Carlo method simulation results are processed in order to construct and study the corresponding optimal hyper-ellipsoidal and smallest coverage regions for bivariate and trivariate distributions with new proposed numerical algorithms for specified probability levels. The results are then further investigated in order to study the accuracy, validity limits and potential confidence region implications for measurement models that exhibit non-Gaussian joint probability density function distributions.

Keywords

Uncertainty analysis Monte Carlo method GUM supplement 2 Multivariate confidence region Pressure metrology 

 

Pressure Uncertainty Analysis for Wound Irrigation Devices

 

Amogh Pawar, Tony L. Schmitz

Abstract

Wound irrigation is defined as the steady flow of a fluid across an open wound for the removal of bacteria, necrotic tissue, and deeper debris. In a wound irrigation process, the surface pressure obtained at the wound is critical. Correct pressure determination ensures that the pressure at the wound due to an irrigation device is enough for the removal of bacteria and foreign debris, but not so high that it causes further tissue damage. Surface pressure measurements were performed for three irrigation devices, including a 500-ml bottle with four holes in the pouring cap, a 60-ml Monoject™ COVIDIEN™ syringe, and an IRIG-8™ Wound Irrigation System from CENTURION™. The irrigation trials were performed by a total of 20 participants consisting of doctors and nurses using the three devices (60 trials) at the Carolina Medical Center Emergency Department, Charlotte, NC. The uncertainty in the pressure measurements was evaluated using both Monte Carlo and analytical approaches, and the results are reported. It is anticipated that this study will help to standardize irrigation pressure measurement within the medical community.

Keywords

Wound irrigation Pressure Uncertainty Monte Carlo 

 

Research on Noise Suppression in Double-Gate Nano-MOSFETs Based on Monte Carlo Simulation

 

Xiaofei Jia, Liang He, Wenhao Chen

Abstract

Experimental observations and simulation results have shown that the dominant noise source of excess noise changes from thermal noise to shot noise with scaling of MOSFETs, and shot noise can be acted by Fermi and Coulomb suppression. But previous studies on shot noise suppression in nano-MOSFETs either ignored the suppression or just emphasized the existence of it but giving no more deep research. Based on Monte Carlo simulation, current noise in realistic nano-MOSFETs is simulated with considering Fermi effect and Coulomb interaction. Thus, shot noise suppression factor (Fano) considering Fermi effect and the Fano considering Fermi effect and Coulomb interaction are obtained. The variation of suppression factors with source-drain voltage, gate voltage, temperature and source-drain doping is investigated with theoretical analysis. The results we obtained are consistent with the experiments and the mesoscopic theoretically explain.

Keywords

Noise suppression Double-gate nano-MOSFETs Monte Carlo simulation 

Abstract for Volume 34, Issue 4, December 2019

 

Economic Impact Studies of Pressure and Vacuum Metrology at CSIR-NPL, India

 

Afaqul Zafer, Sanjay Yadav, Nita Dilawar Sharma, Ashok Kumar, Dinesh Kumar Aswal

Abstract

Measurement standards and metrological activities provide scientific and metrological infrastructure in the country. The Pressure and Vacuum Metrology (PVM) activity has a major role in national and international metrological research and development. The PVM group is successfully providing national calibration and measurement services and fulfilling its national duty as per the mandate of CSIR-National Physical Laboratory (CSIR-NPL). Since last 35 years, no significant efforts were made to assess socio-economic impact of the services provided. Such impact studies are carried out by several National Metrology Institutes, but in India it is still an unexplored area so far. This motivated us to carry out the impact assessment, and present paper is an attempt made in this direction. Systematic studies of the contribution of PVM, established at CSIR-NPL, on national industrial growth and economy, are carried out by assessment of impact. The aim of the present paper is to present the summary of the results thus obtained which is based on the investment made over the years and the estimated benefits to the users. The studies are based on some industrial survey, personal interviews and interactions with stakeholders and sampling of services provided over the years. An overall social rate of return, an indicator of system efficiency, is found to be 180% which is quite high as compared to the present rate of return (8%). This indicates that the PVM activity is quite efficient, and future investment in the activity is safe and would provide excellent returns. The studies are very useful for broader understanding of the economic benefits of PVM and to improve understanding of the decision and policy makers about the relevance, continuation and further investment in PVM activity. This present case study may be explored and applied for other metrological fields also.

Keywords

Economic impact Pressure and vacuum Net present value Benefit-to-cost ratio Social rate of return Industrial survey 

 

 Assessment of Urban Heat Islands Effect and Land Surface Temperature of Noida, India by Using Landsat Satellite Data

 

Mohammad Suhail, M. Shakir Khan, Rashid Aziz Faridi

Abstract

The urbanisation is a process of change in land use by construction activities. Therefore, during construction, uses of low albedo materials give rise in heat absorption capacity that becomes the primary cause of alteration of local climate. Additionally, alteration of land use, viz. conversion of vegetation/forested land into urban built-up land and establishment of heavy industrial units contributes pertinently in local heat budget which leads to the formation of urban heat islands (UHIs). Therefore, the adverse impact of UHIs affected not only ecology and local climate but also socioeconomic setups. In the present work, spatial distribution of UHIs and their causal relationship with land use over NOIDA (New Okhla Industrial Development Authority) city has reported. The data pertaining to study was collected from Landsat-8 OLI–TIRS (operational land imager and thermal infrared sensor) sensor. The results show that two clusters were developed in north and mid-east part of the city due to concentration of high-density building and industrial units. It is recommended that development authority should take environmental concern into consideration before planning industrial land use.

Keywords

Land surface temperature (LST) Land use/land cover UHIs Noida City 

 

Design and Development of Cost-Effective System for the Measurement of Dielectric Constant of Ceramic Materials Using PIC Microcontroller

 

Vishnu Chittan, Mani Kumar Chimpineni, B. Rajesh Kumar, D. Sailaja

Abstract

In the present work, a simple and low-cost instrument is designed to measure the dielectric constant of ceramic materials using the impedance analyser IC AD5933. The AD5933 is highly accurate impedance converter, which provides the impedance value of the sample with respect to different frequencies. The capacitance and dielectric constant values of the prepared samples are derived from the impedance. A PIC microcontroller is used to interface the circuitry of the impedance analyser and display the measured data on the LCD. In addition, the measured data are exhibited on the serial console of the microcontroller. The measured values were compared with standard impedance analysing device HIOKI-LCR Hi-tester353250.

Keywords

PIC microcontroller AD5933 circuit Impedance Capacitance Dielectric constant 

 

Total Column Ozone, Precipitable Water Content and Aerosol Optical Thickness Over Atigre Village, a Tropical Station: First Observations

 

Dada P. Nade, Swapnil S. Potdar, Rani P. Pawar, Santosh T. Mane, S. Chandra, A. Taori, Devendraa Siingh

Abstract

In this paper, we report first-time observations of total column ozone (TCO), aerosol optical thickness (AOT) and precipitable water content (PWC) at five different wavelengths using compact, handheld, multichannel sun photometer (Microtops II ozonometer) at Atigre village (16.74°N latitude, 74.37°E longitude, 604 ms altitude above sea level). The three optical filters at wavelengths 305 nm, 312 nm and 320 nm are used to detect the TCO, while two optical filters 936 nm and 1020 nm are used to detect the PWC and AOT, respectively. We have been collecting data from September 1, 2017, and 122 days are selected from September 1, 2017, to December 31, 2017, to present as first observations of TCO, AOD and PWC. The mean values of TCO, AOT and PWC are found to be 261.2 (± 9.22) DU, 0.25 (± 0.04) and 1.98 (± 0.79) cm, respectively, during this period. The TCO measurements taken by the Microtops II ozonometer are compared with the ozone monitoring instrument satellite data over Atigre. We found that PWC and AOT values are negatively correlated (− 0.54) during monsoon season, while they show positive correlation (0.63) during other seasons with 90% significance level. The diurnal variation of TCO, PWC and AOT differ in monsoon and the post-monsoon season.

Keywords

Microtops II ozonometer Total column ozone (TCO) Aerosol optical thickness (AOT) Precipitable water vapor (PWC) 

 

Measurement of Benzo (a) pyrene in PM10 Collected in New Delhi

 

Jyoti Pokhariyal, Anubha Mandal, Shankar G. Aggarwal

Abstract

Polyaromatic hydrocarbons (PAH) are the compound which consists of multiple benzene rings bonded in straight, groups or angular forms. They are also found in atmospheric aerosols. In the atmosphere, they can be emitted primarily as a result of incomplete combustion of natural sources (fossil fuels, forest fires, smoke etc.) or anthropogenic sources (coal burning, vehicular emissions, smoke, etc.) or secondarily by atmospheric processes. Depending on the anthropogenic sources, PAHs may occur in significant concentration in urban and industrial ambient air, i.e., bounded with particulate matter (PM). A particle whose aerodynamic diameter is ≤ 10 µm is called PM10. Benzo(a)pyrene (BaP) is among the most toxic and carcinogenic PAHs. Both PM10 and BaP are among the 12 criteria pollutants listed in Indian National Ambient Air Quality Standards (NAAQS). In this paper, BaP concentration in PM10 collected in a representative site of New Delhi was studied during the year 2014–2015. The average concentration of BaP is varied from 0.04 to 25.7 ng m−3. The uncertainty components in measurements were also estimated along with statistical analysis. The most significant uncertainty component is the purity of the BaP standard which has the highest uncertainty contribution as 77%.

Keywords

NAAQS PM10 PAHs Benzo (a) pyrene (BaP) 

 

Report of a Multilateral Accurate Measurement Comparison on a High-Precision Multimeter to Evaluate the Traceability Transfer from INRIM in the Field of Low-Frequency Electrical Quantities

 

Flavio Galliana, Marco Lanzillotti

Abstract

As the calibration activity of modern electrical secondary laboratories operating in the five low-frequency quantities is carried out by means of high-precision digital multimeters (DMMs), it is of fundamental importance for their correct technical surveillance through suitable inter-laboratory comparisons (ILCs). The laboratory for calibration of multifunction electrical instruments of the National Institute of Metrology Research (INRIM-Lab) provides bilateral and multilateral ILCs involving high-precision DMMs to check the measurement capabilities of electrical laboratories. In particular, this paper deals with the last multilateral ILC that INRIM-Lab provided and carried out as reference measurements’ provider to which took part twelve Italian-accredited laboratories divided into two loops. The ILC was involved in a high-precision 8.5 digit high-precision DMM to be verified in a grid of about forty measurement points. The 2σ relative uncertainties of the INRIM-Lab calibrations ranged from 1.6 × 10−6 to 1.5 × 10−4, while those of the laboratories ranged from 2.0 × 10−6 to 2.2 × 10−3. The ILC had satisfactory results confirming the correctness of both the dissemination from INRIM and the accreditation process by the Italian accreditation body for calibration laboratories.

Keywords

Inter-laboratory comparison Low-frequency electrical quantities Multimeter Multifunction calibrator Measurement compatibility Measurement uncertainty Normalized error 

 

Vertical Profiling of Radio Refractivity and Associated Parameters Using Tethered Balloon over New Delhi

 

Ahlawat, S. K. Mishra, M. V. S. N. Prasad, C. Sharma, V. Goel, S. R. Radhakrishnan, B. Gupta

Abstract

Atmospheric radio refractivity and its vertical gradient affect electromagnetic (EM) wave propagation mostly in the lower troposphere. The vertical profiles of the radio refractivity over New Delhi are very limited that inspired us to study the same using tethered balloon facility. Here, we investigated radio refractivity and its gradient over New Delhi (28°38′10″N, 77°10′17″E) using radiosonde balloon observation for one week (February 21–27, 2014). Vaisala RS 80 radiosonde device used during this experiment comprised of the individually factory-calibrated temperature, pressure and humidity sensors. The resolution of temperature sensor, pressure sensor and humidity sensor is 0.1 °C, 0.1 hpa and 1% RH, respectively. The refractivity measured using radiosonde has been observed to be reduced by 8.6% at 930 masl (mean above sea level) relative to that of ground level (i.e., 230 masl) during up-leg observation (7:00–7:30 PM), while the same has been found to be increased by 10.8% at ground level relative to that of 930 masl during down-leg observation (3:30–4:00 AM). Though it is a small set of information pertaining to refractivity observations using tethered balloon, certainly it can provide micro-insights of the meteorological effects on radio wave propagation better than that of routine experiments. The present study could be crucial for understanding the probable effects on radio wave propagations within atmospheric boundary layer over the study region and would reduce the underlying uncertainties associated with such measurements.

Keywords

Refractivity Tethered balloon Gradient Atmospheric boundary layer 

 

Volume Measurement of Large Volumetric Vessel Using Tap Water

 

Goutam Mandal, Anil Kumar, Sanjoy Mandal, D. C. Sharma, Manoj Kumar

Abstract

Being a National Metrology Institute (NMI) of India, CSIR-National Physical Laboratory, India (NPLI), provides calibration services to the industries to improve the quality of products. In the last couple of years, NPLI has provided number of calibration services of volumetric vessels up to 2000 L (unique facility in India) to the petroleum industries, flow meter manufacturing industries, etc. In general, for the calibration of volumetric instruments, distilled water is used as the medium but in the case of large volumetric vessels (say 2000 L), the use of distilled water is not practical. Hence, tap water is used and every time the density of tap water is measured against distilled water to improve the accuracy of the measurement. In this process, we have achieved measurement uncertainty less than 50 mL in 2000 L. But due to influencing factors of environmental conditions of laboratory, change of density of supplied tap water, conversion factors of tap water and distilled water in desire temperature, we have restricted our calibration and measurement capability (CMC) up to 100 mL in 2000 L. In this paper, we have discussed the detailed procedure of volume measurement of 2000-L volumetric vessel and its associated uncertainty calculations using gravimetric method.

Keywords

Gravimetric method Volume Density Tap water Uncertainty 

 

Ambient Air Quality and Its Sources Surrounding to Hydropower Projects in the Satluj Basin, Northwestern Himalaya, India

 

Bhim Chand, Jagdish Chandra Kuniyal, Raghubir Chand

Abstract

Ambient air quality in terms of particulate matter < 10 µ (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2) and ammonia (NH3) was monitored in the upper Satluj basin under-construction stage of Shongtong-Karcham (450 MW) and commissioned stage of Rampur (412 MW) hydropower projects. PM10 ranged from 102.8 to 111.9 µg m−3 with a mean of 106.4 ± 1.2 µg m−3 in summer season at Shongtong-Karcham, while at Rampur project it was found from 17.8 to 65.5 µg m−3 with a mean of 50.9 ± 6.1 µg m−3. Particulate pollution is high under a construction project stage as compared to a commissioned project. While gaseous pollutants like SO2 (8.2 ± 1 µg m−3), NO2 (10.2 ± 0.8 µg m−3) and NH3 (11.2 ± 1 µg m−3) were found relatively high at Rampur compared to Shongtong-Karcham where SO2 (7.9 ± 0.6 µg m−3), NO2 (4.8 ± 0.6 µg m−3) and NH3 (8.9 ± 1.1 µg m−3) were found relatively low. The particulate pollutants crossed its permissible limit (100 µg m−3) as set by National Ambient Air Quality Standards, India, while gaseous pollutants were under permissible limit. HYSPLIT and concentrated weighted trajectory analysis indicate that hydropower project activities have been major local sources of particulate (> 80 µg m−3) and gaseous pollutants, although overall air quality index is good (0–50).

Keywords

Hydropower projects Particulate matter < 10 µ Sulfur dioxide Nitrogen dioxide Sources Satluj basin Northwestern Himalaya 

 

Design Investigations of Axis-Symmetrical Force Transducers

 

Richa Saxena, Sanjoy K. Ghoshal, Harish Kumar

Abstract

The presented investigation is an attempt to discuss the design-related issues of force transducers of ring shape. The force transducer has been analysed for deflection, stress–strain. A comparison has been made for the deflection of the transducer in accordance with the analytical, computational and experimental methods. There has been consistency of deflection as reported by the methods mentioned above. The paper further reports the comparison of the reiterated findings of a ring-shaped force transducer discussed by Chen et al. (Sens Actuators A Phys 139:66–69, 2007). It has been found that the previous findings seem inconsistent and adequate attention is required.

Keywords

Force transducer Stress–strain Deflection Finite element analysis Castigliano’s theorem 

 

GPS-Based Time Transfer Using Low-Cost Receivers

 

Michael J. Wouters, E. Louis Marais

Abstract

GPS-based time transfer can be used to establish a traceable link between a national time standard and a remote user’s standard. Equipment cost can be a consideration in such applications, and the GPS receiver used can be a significant component of this cost. We consider the use of low-cost timing receivers in time transfer, establishing the requirements for such receivers. Three suitable receivers are characterized, using software we have written for the Open Traceable Time Platform, an open source project developing a system for legally traceable time and frequency. The tested receivers were found to be suitable for all but the most demanding applications.

Keywords

GPS receiver Time transfer Traceability 

 

Analysis of Random Factors Affecting Measurement Accuracy of Portable Coordinate Measuring Arm

 

Chang-Hyon Rim, Bai-Qing Sun, Yong-Gun Kim, Pyol Kim

Abstract

To improve the measurement and calibration accuracy of Portable Coordinate Measuring Arm, it is very important to accurately identify the system and random errors of the measuring machine. From the kinematic error model, system errors can be identified during calibration. But identifying random errors remains a difficult problem. First, we use the SolidWorks software to analyze the structure of each joint. Second, CETOL 6σ tolerance analysis software is used to calculate the random error of the probe generated by the clearance of bearings in each joint. Finally, the random error due to the systematic uncertainty of the rotary encoder is calculated. The experimental results show that the total value of the random error due to the bearing clearance, the systematic uncertainty of the rotary encoder and the thermal expansion of the mechanical structure according to the temperature variation does not exceed 0.1112 mm. This value is theoretically the limit of the single point repeatability accuracy that can be achieved by this measuring machine. The use of the CETOL 6σ not only allows the design to be carried out scientifically, but also reduces production costs.

Keywords

PCMA Random error Measurement accuracy Calibration 3D tolerance analysis 

 

Noninvasive Temperature Measuring and Early Fault Detecting System for Manufacturing Industry

 

Dilip Kumar, Kumar Gaurav Suman

Abstract

Over the past few years, in industry the maintenance workers are still using handheld equipment to measure and collect the data periodically to monitor the health of the running machine. In industry, the bearing temperature is an intensively studied parameter for indicating various faults of a rotating machine because mainly the life of the machine parts reduced more than 50% when the bearing temperature exceeds 70 °C that may results catastrophic failures. This paper presents noninvasive temperature measuring system for predicting the early faults occurring in the running machine. The normal operating temperature of a machine is 60–70 °C. The Hall effect sensor can measure the increased bearing temperature remotely. In addition, the measured Hall effect sensor output is greater in case of stainless steel than aluminum plate at 4 cm. The importance of length/diameter (L/D) ratio and demagnetization curve is also illustrated for the selection of permanent magnets. By using cloud, the data gather at higher speed can be stored, monitored, analyzed and control remotely by industrial staffs to predict the mechanical faults occurring in a machine well in advance because the cost implications are massive when they go wrong.

Keywords

Bearing Cloud Sensor Temperature Wireless Permanent magnet Predictive maintenance 

 

A Modified Acid Digestion Method for Analysis of Gold in Geological Samples: A Comparative Study

 

Prasun Ghosh, Haridas Mandal, B. Sirisha, Ujjal Sen, Sudip Goswami, N. V. R. Kiran

Abstract

Quantification of gold in geological samples using fire-assay technique is a well-established and recommended method worldwide. However, the method is laborious, complicated, sluggish, and health hazardous. Only a well-trained chemist can perform gold analysis through fire assay routinely. Although classical aqua regia digestion for determination of gold yields high throughput, this method too has disadvantages of sample nature dependency, thus brings down the recovery levels. Herein, we report a modified aqua regia digestion method, followed by solvent extraction using methyl isobutyl ketone for the accurate and precise estimation of Au in variety of geological samples of different genre in broad concentration range. Roasting of sample was avoided and excess of aqua regia (6 times or higher than of sample weight) was used to bring all gold in aqueous phase. This method was applied to soil and rock samples and the results obtained were compared with conventional fire-assay technique. The analytical results for international reference materials of gold (SRM/CRM) measured by the proposed method were in close agreement with those obtained by fire-assay method and recommended values. Very low detection limits were achieved in the proposed method (1 ng/g by GF-AAS and 100 ng/g in F-AAS). This method also works satisfactorily at moderately higher concentration of gold in rock samples, at least up to 15 ppm. Thus fire-assay technique may be substituted by the proposed method for detection of Au in 10 ppb–15 ppm concentration range in the geological samples mentioned under present study.

Keywords

Analysis of gold Aqua regia MIBK Fire assay GF/F-AAS CRM/SRM Field geological samples 

 

Effects of Waveforms Distortion for Household Appliances on Power Quality

 

Hala Mageed, Adel S. Nada, Salama Abu-Zaid, Rehab S. Salah Eldeen

Abstract

Harmful effect of harmonics is considered one of the main factors that badly affect the electricity meters’ accuracy and power quality of distribution systems. In this paper, the impact of harmonics generated by various household appliances has been investigated. Household appliances have been divided into four groups according to the similarity of their current and voltage waveforms. The appliances have been collected together according to the reason of the year and time to analyze their waveform. Experimental measurements have been performed using a standard CALMET-TE30 three-phase power quality analyzer. Measurement uncertainty calculations have been taken into consideration to acquire the actual measurement results. The waveforms of these results have been precisely plotted using a specially designed MATLAB program.

Keywords

Household appliances Power quality Nonlinear loads Harmonics Power factor