Fire Safety Science Digital Archive

An instrument has been developed for measuring heat flux in the range from 0 to 10 W/cm^2. It is of robust construction, suitable for outdoor use and designed so that it can be mounted flush with a surface to which the heat transfer is required to be measured. The output of the instrument is proportional to the heat flux falling on it in the range from 0 to 5 W/cm^2 and at 8 W/cm^2 the deviation from direct proportionality is not more than 6 per cent. The sensitivity is sufficient to enable a change in heat flux of 0.1 W/cm^2 to be detected. By using the heat flux meter with and without an infra-red transmission window on the front values of both the radiated and convected heat transfer can be obtained. The instrument is not very sensitive to draughts even without the transmission window, but with it the output is rendered completely unaffected by draught for all practical purposes.