Experiments with a Heat Camera for Recording Temperature Distribution in Foods during Microwave Heating*

Surface temperature patterns of foods being heated in a microwave oven were determined by infra-red television through a screen door permeable to IR radiation but not to microwaves. Isothermic patterns of the entire food surface exposed could be followed continuously during the heating cycle and photographed at a maximum rate of eight exposures per second. The method may prove useful in the development of microwave ovens to study the effects of oven and sample configuration, couplings, etc., on the field and temperature distribution, and further study seems justified to overcome present limitations.