EFFECT OF FLUID TEMPERATURE ON HOT-WIRE ANEMOMETERS AND AN IMPROVED METHOD OF TEMPERATURE COMPENSATION AND LINEARIZATION WITHOUT USE OF SMALL-SIGNAL SENSITIVITIES

Theoretical considerations and experimental results indicate that except for a very slight temperature effect on fluid properties, the square of the hot-wire anemometer voltage is, within normal experimental accuracy, linearly dependent on the fluid temperature when operating in the constant wire temperature mode. This permits use of a greatly simplified calibration procedure. When used with the three-term velocity calibration, a simple analogue circuit is available to give a temperature compensated and fully linearized instantaneous velocity signal. After setting of calibration constants, no further circuit adjustments are required for different velocities and fluid temperatures.