Method and gas mixture for calibrating an analyzer

摘要

A method of measuring the concentration of a component in a sample gas comprises the steps of: determining the flow rate at sonic velocity of a sample gas through a critical orifice; determining the flow rate at sonic velocity of a calibration gas through the critical orifice; comparing the flow rate of the sample gas with the flow rate of the calibration gas; formulating the calibration gas with an additional gas to adjust the flow rate of the calibration gas to approximately equal the flow rate of the sample gas through the critical orifice at sonic velocity, thereby creating a balanced calibration gas; calibrating the analyzer with the balanced calibration gas, wherein a concentration reading of the component from the analyzer is compared with a known concentration of the component in the balanced calibration gas; and measuring the concentration of the component of the sample gas using the analyzer.