• Characterization;
  • chilled convenience meals;
  • power output;
  • temperature variability;
  • testing

Summary There is a need for standard methods of testing domestic microwave ovens that relate to their reheating performance with chilled convenience meals. The investigations reported here have produced a simple procedure for comparing the three most important reheating characteristics of a domestic microwave oven: its ‘true’ power; heating variability; and repeatability. The tests are relatively simple to do, and require only a few additional items of equipment to those that a laboratory performing existing output power tests would already possess. Three identical tests are required: one with a liquid test material, one with a solid and one with a combination of the two components. One additional stage is done with the liquid test material. The data produced can be reduced to three numbers, which are measures of the true power, variability and repeatability of the oven. A further simple analysis, which weights the relative importance of each factor to the consumer, would produce a single value for the oven's relative reheating performance. Ovens with unusual or extreme performance characteristics can therefore be identified easily.