Particles in High-Pressure Cylinder Gases

Abstract

An improved test protocol is presented for the measurement of particle concentrations in high-pressure cylinder gases. With the screening method, particles entrained in a cylinder gas can be collected and chemically analyzed for the isolation of particle sources. Results are presented for argon, helium, and nitrogen cylinder gases. Many fine particles are formed from the trace organic vapors present in the cylinder gas by gas-to-particle conversion occurring downstream of such pressure-reducing devices as an orifice plate. It is demonstrated that these fine particles in the cylinder gas can be significantly reduced by as much as three orders of magnitude by the insertion of an appropriate purifying stage before the pressure-reducing devices.