Temperature correction of flexible thermal shear stress sensor for underwater measurements

The fluid temperature difference between practical operation and its original calibration procedure can cause an unacceptable error for micro thermal shear stress sensors. Thus, the temperature correction is necessary when the working water temperature is different from the original calibration temperature. By analyzing the temperature dependence of the overheat ratio and coefficients of the sensor's behavioral equation, a correction method is presented. Laminar flow experiments with changeable temperatures are carried out. The results show that the influence of water temperature can be minimized, and the relative errors of sensor output at water temperature of 25°C and 28°C can be falling to 0.82% and 0.83% from 23.7% and 37.1%, respectively.