A NEW PRIMARY GAS FLOW STANDARD FOR FLOW RATE MEASUREMENT FROM 0.001 TO 1000 NANO mol/s

Wu Jian, Chua Hock Ann

Abstract

A primary gas flow standard was designed and developed in SPRING for the calibration of gas flow meters or leak rate standard at nano-flow rate range of 10^-6 to 10^-12 mol/s. It is also used to generate very low gas flow for SPRING’s continuous expansion vacuum primary standard. The primary standard consists of two piston-cylinder flow units with diameters of 10 mm and 25 mm, which provide wider measurement ranges. A stepping motor is used to drive the piston moving at precise speed via a digital micrometer. Two methods, constant pressure method and constant volume method, are used for the measurement of flow rate. Flow meters can be calibrated automatically using a software program developed at SPRING. The expanded measurement uncertainty of the primary gas flow standard is estimated to be 1% of the readings.

Keywords

Nanofluidics, Gas flow, Primary Standard, Measurement Uncertainty

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PWC-2006-TC9-022u.pdf

DOI

-

IMEKO TC

TC9 - Flow Measurement

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