25 research outputs found

    Estimation of uncertainty of effective area of a pneumatic pressure reference standard using Monte Carlo method

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    The current paper presents a comparative investigation of the experimental as well as simulated evaluation of effective area and the associated uncertainties, of a pneumatic pressure reference standard (NPLI-4) of CSIR-National Physical Laboratory, India, (NPLI). The experimental evaluation has been compared to the simulated estimation of the effective area obtained through Monte Carlo method (MCM). The Monte Carlo method has been applied by taking fixed number of trials (FMCM) and also by trials chosen adaptively (AMCM). The measurement uncertainties have been calculated using the conventional method, i.e., law of propagation of uncertainty (LPU) as well as MCM. Experimentally, the NPLI-4 has cross-floated against our newly established pneumatic primary pressure standard (NPLI-P10), which is a large diameter piston gauge. An excellent agreement in effective area and measurement uncertainty has been observed between these approaches

    Improved Measurement Capabilities in Pneumatic Pressure Measurements at NPLI Through Re-establishment of the Traceability Chain

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    This work presents, in brief, the recently concluded extensive in-house inter-comparison of the pneumatic pressure standards at CSIR-National Physical Laboratory, India (NPLI) and the resulting marginal improvement in our measurement uncertainties. The measurements are traceable to the Ultrasonic interferometer manometer (UIM), our low-pressure primary pressure standard as well as to the national primary standard in pneumatic pressure, NPLI-P1. The inter-comparisons and the subsequent estimations of measurement uncertainties, starting from the UIM, were carried out in the overlapping pressures, ranging from 0.01 to 40 MPa. In addition, the large-diameter piston gauge, the pneumatic primary standard was also used to establish the traceability chain. A summarized description of the extensive exercise undertaken is given herein which describes the stability and the excellent agreement with previously reported results as well as successful improvement owing to better control over experimentation as well as environmental factors