A small, Fast-Response Probe to Measure Composition of a Binary Gas Mixture

Abstract

A probe to measure the concentration of the components in a binary mixture of gases is described. The probe is simple to construct and quite rugged. It samples from a very small volume, has a fast time response and can very easily detect 1% of helium in nitrogen. The explanation of the principle of operation is a good example of the power of dimensional analysis when applied to what may seem to be quite a complicated and unfamiliar problem. The analysis suggest several experiments which in turn lead to a more detailed understanding of the probe and improvements in its design.