Mass Flow Measurement Using a Hydrocarbon Trace-Gas Technique

摘要

A mass flow measurement technique for hydrocarbon-free air flows is presented. The technique is based on the method-of-mixtures using ethylene as the trace-gas. The method is easy to implement, inexpensive and has proven to be a viable alternative to traditional techniques under circumstances when traditional techniques are unsuitable. The components of the system, operating procedure and uncertainty estimations are discussed. Mass flow measurement uncertainties less than 2percent can easily be achieved with the technique. The primary limitation of the method is the long response time under conditions of low absolute pressure. Preliminary development of a new silicon carbide-based hydrocarbon sensor that has the potential to significantly improve response time is also discussed.