Final report on the key comparison CCM.P-K4.2012 in absolute pressure from 1 Pa to 10 kPa

Abstract

The report summarizes the Consultative Committee for Mass (CCM) key comparison CCM.P-K4.2012 for absolute pressure spanning the range of 1 Pa to 10 000 Pa. The comparison was carried out at six National Metrology Institutes (NMIs), including National Institute of Standards and Technology (NIST), Physikalisch-Technische Bundesanstalt (PTB), Czech Metrology Institute (CMI), National Metrology Institute of Japan (NMIJ), Centro Nacional de Metrología (CENAM), and DI Mendeleyev Institute for Metrology (VNIIM). The comparison was made via a calibrated transfer standard measured at each of the NMIs facilities using their laboratory standard during the period May 2012 to September 2013. The transfer package constructed for this comparison preformed as designed and provided a stable artifact to compare laboratory standards. Overall the participants were found to be statistically equivalent to the key comparison reference value.

A transportable refractometer for assessment of pressure in the kPa range with ppm level precision

“…The procedure was thus not optimized for speed. 4 In practice, the DUT can be separated from the refractometer and the pressure can be assessed using a suitable high-performance differential pressure measurement instrument.…”

“…In the SI-system of units, the realization of the Pascal relies on mechanical primary devices such as pressure balances and liquid manometers that realize pressure as a force per area [1][2]. Although current conventional techniques demonstrate excellent performance under optimal conditions and handling [1,3,4], their performance have remained nearly unchanged for decades. They are often limited in terms of working range, in particular pressure balances, which have a lower limit given by the mass of the piston, and they need to be firmly stationed in a highly stabilized laboratory, requiring either the system to be characterized to be transported or the use of transportable secondary standards to calibrate systems out in scientific laboratories or industrial facilities.…”

Development and characterisation of a low pressure transfer standard in the range 1 Pa to 10 kPa

“…In the recent key comparison CCM.P-K4.2012, in the same range [1], the pilot laboratory has developed a transfer standard based upon a CDG 100 Pa and a special 10 kPa RSG. Over the course of the comparison, this latter, with a resolution of 0.01 Pa, showed a stability between a few ppm at 10 kPa to about 1×10 -4 at 100 Pa, allowing one to rescale the CDG which could consequently provide a quite low uncertainty contribution as a transfer standard between 1 and 100 Pa.…”

Towards Photonic based Pascal Realization as a Primary Pressure Standard

“…Since then many new devices and techniques have tried, but none have been able to surpass the accuracy of the mercury manometer. An Ultrasonic Interferometer Manometer (UIM) constructed at NIST claims the lowest uncertainties in the world [1,2], however a new technique utilizing the refractive properties of gas will replace the 400 year reliance on liquid mercury for the highest accuracy pressure measurements.…”