Calibration and use of hot wire probes for steady state measurements in low density flows

In recent years the use of hot wire probes for steady state measurements in low density flows has proved very valuable in extracting information concerning flow properties. In interpreting hot wire measurements in low density flows, it is imperative that the heat loss to the wire supports be accurately taken into account. In the present paper, a detailed analysis and calibration procedures for the direct evaluation of the end-loss correction factors for a moderate aspect ratio hot wire have been set out, and experimental verification done to establish the validity of the technique.