High Pressure Capillary Flow Meter for GC

Abstract

The construction and operation of a relatively inexpensive capillary flow meter for use in monitoring low flows at pressures to above 100 psig is described. Once calibrated, the flow meter is a rapid, convenient, reliable monitor and readily illustrates changes in flow due to leaks or blockages. It can serve as a replacement for the standard bubble meter. An advantage of the capillary orifice flow meter, In addition to its capacity to read very low flows, is that, even when used for moderates flows, it does not exhibit the flow reading instabilities often observed with floats because of static effects when using very high purity gases.