MAPAN

In this research, a dynamometer was designed, constructed and calibrated to measure the forces and moments applied on tillage implements. This dynamometer is able to measure the three orthogonal forces acting on the implement and the three moments acting around the orthogonal axes, up to a maximum force of 20 kN and a maximum moment of 20 kN m. The dynamometer uses two extended octagonal ring transducers mounted in a back-to-back arrangement with their axes at right angles and has a tubular torque meter for torque measurement. For mechanical design of the dynamometer frame and its units, the finite element method and CATIA software were used. The device was machined from the solid part and high tensile steel. The forces and moments acting on the dynamometer were measured by using the strain gauge bridges on two extended octagonal ring transducers and on the torque meter tube. The results of data analysis, including forces applied on the dynamometer, the designing method of rings and torque meter tubes, the mounting arrangement of load cell parts on each other, the mounting method of load cell on frame and the position of strain gauge on load cell, in other words, the position of different parts of the dynamometer relative to each other has been explained in this paper. Calibration of the measurement unit was done by a calibration system which was designed for static calibration of the triaxial dynamometer. The results of calibration of the measurement unit showed that the designed and constructed dynamometer has appropriate precision, sensitivity and good repeatability for measuring the desired forces and moments. The results showed a high degree of linearity between output voltage of bridges and applied forces and moments. The interaction effects of the applied forces and moments were very negligible.

The cryogenic current comparator has played a central role in the realisation of electrical quantum standards over the last 40 years. It is the method of choice for National Measurement Laboratories in realising a quantum Hall effect primary standard of resistance. Single electron transport devices are expected to provide a primary standard of current within the next few years and this paper considers how they will be integrated into electrical metrology.

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.

A study on natural radioactivity in soil around Tummalapalle uranium mineralised region was carried out. The aim of this study was to find the activity of primordial radionuclides 226Ra, 232Th and 40 K over the span of 5 years from 2018 to 2022 to understand the trend of activity of radionuclides in soil and impact of mining activities on the surrounding soil. The overall average activity of 226Ra, 232Th and 40 K over the years has been found to be 25 Bq/kg, 40 Bq/kg and 478 Bq/kg, respectively. The 226Ra and 232Th activities have been found to be less, whereas 40 K activity has been found to be slightly higher than the worldwide average of 32, 45 and 412 Bq/kg. The activity of radionuclides over the years does not show any increasing trend, which indicates that there is no impact of mining activities in the region on the soil in surrounding environment. Radium equivalent for soils was found to be 117.10 Bqkg−1, which is lower than the recommended limit of 370 Bqkg−1, and the annual effective external dose was found to be 345.56 µSvy−1, which is less than the worldwide average of 460 µSvy−1. External hazard index was found to be 0.35 Bq kg−1, which indicates insignificant radiation hazard from natural radionuclides in soil.

Mining activity and metal extraction processes have been identified as one of the major pathways through which natural radionuclides are accumulated in the terrestrial environment. Exposure to excessive radiation from natural radionuclides can cause deleterious health hazards to man. In this study therefore, the activity concentrations of primordial radionuclides (40K, 238U and 232Th) were measured in rock, soil, tailings and water samples collected from abandoned iron ore mines in order to estimate the radiological impacts associated with the previous mining and metal extraction activities within the environment of abandoned Itakpe iron-ore mines. Gamma spectrometry utilizing a well calibrated NaI(Tl) detector was employed for the measurements. Results show that the average activity concentrations of 40K, 238U and 232Th are 1084 ± 581, 11.0 ± 7.7 and 5.0 ± 1.8 Bq kg−1 respectively for rock samples and 415.6 ± 197.5, 12.8 ± 5.7 and 8.8 ± 5.8 Bq kg−1, respectively for soil samples. The activity concentrations of the three radionuclides are much lower in water samples compared to rocks and soil. Radiological hazard indices calculated from the activity concentrations show that the mining activities have little or no negative impacts on the environment as the radiological risk indices obtained are all lower than their permissible limits.

Length measurement has been an indispensable part of human life since the ancient era till present days. Length and area measurement got importance from very early Indus Valley civilization for construction of roads to measurement of agricultural land. In India, length measurements were defined in Indus Valley civilization and rulers had rules for length measurements. Mughal and British adopted the measurement system contemporary to the international system of units available and were used in the country. During twilight years of the regime of British government, plans for setting up an institute for measurement standards were made and a national institute of measurements was founded in 1942. Within the first decade of laying the constitution of India, SI units were adopted. In this paper, we describe the history and advancements in the progress towards length measurement through its various redefinitions from time to time. It covers the evolution of SI unit of length “Metre” through its diversified redefinitions from the ages of body parts to latest quantum standards.

The technological enhancements and new startups in India have led to a tremendous increase in the power demand. The grids are being made smart, more efficient and reliable to meet not only the growing energy demands but also to prevent blackouts. The synchrophasor technology is evolving, explored and used by the power sectors for real-time measurements with phasor measurement unit (PMU) as the main elemental device. Industries developing PMUs must ensure that it should comply the IEEE C37.118.1-2011 and C37.118.1a-2014 synchrophasor standards, as the corrective action taken by power grid in real-time environment will depend on the PMU data. The optimization of PMU ensures that the measurement results are as per the IEEE synchrophasor standards leading to improvement in its performance. Here, we had evaluated the performance of an industrial PMU using CSIR-NPL PMU calibration system. The evaluation was done under static and dynamic conditions. This analysis represents the capability of PMU testing and calibration at CSIR-NPL and also ensures that the PMU that will be used in real time on the fields reports precise data. PMU-Cal facility can handle all the steady-state and dynamic-state tests for both M class and P class configured PMU at all desired frame rates. This system is traceable to its respective primary standards and is functional to cater the needs of power sector in terms of PMU calibration and testing.

UTC(NIM), which is developed and maintained by NIM, is the time and frequency primary standard in China. UTC(NIM) is generated originally by a clock ensemble, and is traced to UTC by participating in TAI cooperation with GNSS time and frequency transfer methods. TWSTFT earth station has been established at NIM new campus to join the Europe–Asia link. In this paper, the new development on the realization of UTC(NIM), the GNSS time and frequency transfer and TWSTFT and our briefly future plan are introduced.