Thermal mass flow meters are used in conjunction with Continuous Emission Monitoring System (CEMS) systems for flue gas or air emission monitoring.
Flue gas comes from many combustion sources, including furnace exhaust gases, thermal oxidizers. Measuring the gas flow is necessary to calculate the total gas mass over time, which is a requirement for many environmental regulations.
Flue gas streams are relatively high volume and in large channels. A single point measurement may not give accurate values for the overall flow profile. It is more accurate to measure homogeneously in a large diameter pipe. For this reason, more than one thermal flow meter is used and the average of the measured flow values can be calculated in control systems.
The sensor requires a straight pipe distance at the inlet and outlet, and in such a case, the measurement error rate is minimized only when multi-point flow measurement is preferred.
Increasing the number of measuring points helps to improve flow measurement accuracy in large channels.
