Like the flue gas, this medium has a higher temperature, contains more impurities such as solid dust, the general application of large caliber, flow rate range is relatively wide, so the measurement is more difficult, so in the selection and use of flue gas flow timing should pay attention to the characteristics of the power plant flue wind speed, pay attention to the principle of choosing sensors, It is also necessary to pay attention to the wear resistance, corrosion resistance, dirt resistance and high temperature resistance of the sensor, and select the appropriate measurement position to ensure the measurement accuracy.