In order to achieve turbulence measurements in supersonic flows the frequency response of CTA is tested and improved. A fast and convenient technique to determine electrically the frequency response is proposed; the response is also tested by direct heating of the wire by means of a laser beam. The two techniques are in good agreement. Under certain experimental conditions (M=2,Re&fgr;=400) it is possible to use CTA with a satisfactory frequency response up to 250 kHz and overheat ratios down to 0.07. In these severe operating conditions, the square‐wave test technique seems to be not sufficient to ensure optimum settings and it is necessary to use symmetrical bridges with fine adjustment of offset voltage.