Developments in the Pressure field at CEM

Nieves Medina, Salustiano Ruiz, Carmen Matilla

Abstract

In the near future new pressure standards will be operative at CEM. These standards together with the existing will provide traceability to the whole pressure range. These standards are a mercury column, a force piston gauge and a static expansion system.<br /> The mercury column is a U-shaped steel tube filled with mercury. Its measurement principle is Torricelli´s law. The height difference between the two columns is measured by means of a single-beam helium–neon laser interferometric system. Its measurement range is from 1 kPa up to 130 kPa in absolute, relative and differential modes.<br /> The force piston gauge is a recent acquisition. It is a pressure standard designed to cover the range from less than 1 Pa to 15 kPa gauge and absolute pressures. The instrument operates on the piston gauge principle in which the pressure on the piston is measured by a forced balanced load cell.<br /> The static expansion system is based on Boyle´s law with some corrections. This standard will work from 10^-4 Pa to 103 Pa. This system consists of two large 100-litre volumes, two 1-litre volumes and a 0.5-litre volume. The system is evacuated by means of two 300 l/s-turbomolecular pumps connected to the large vessels. Both of them will be connected to a primary dry pump.

Keywords

mercury column, force piston gauge, static expansion system

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IMEKO-TC16-2007-036u.pdf

DOI

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IMEKO TC

TC16 - Pressure and Vacuum Measurement

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