Heat flux transducer measurement error: a simplified view.

Heat flux transducers (HFTs) provide a simple and direct measurement of body heat exchange. Regrettably, HFTs perturb the heat flux at the measurement site, resulting in underestimations of the true heat flux. Equations to correct the discrepancy are available, but most require high-precision temperature measurements above and/or below the transducer and/or deep within the body tissues. Because this is not always feasible, the equations are of limited practical benefit. A theoretical basis for the magnitude of the correction factor in relation to the thermal resistances of the materials both above and below the HFT has been developed and has been verified experimentally. The theory is presented in a graph that can be used to drive the HFT correction factor directly or as a guide to know that heat flux was measured within a certain accuracy. This may obviate the use of complicated procedures and equations to perhaps needlessly apply a small correction factor to HFT data.