Abstract: A calorimetric wattmeter for testing a microwave oven. The wattmeter comprises a housing which defines an interior chamber for holding a quantity of a microwave absorbing liquid. Attached to the housing is a thermometer having a sensor portion which extends into the interior chamber and an indicator portion which moves in response to temperature changes sensed by the sensor portion. Additionally, rotatably attached to the housing is a scale which circumvents the indicator portion and includes indicia thereon for correlating the position of the indicator portion to a microwave oven wattage reading. The scale is selectively rotatable for purposes of resetting the microwave oven wattage reading to zero relative to the position of the indicator portion. The housing also includes a pair of neon gas filled enclosures attached thereto for providing a visual indication of the presence of microwaves.

Abstract: A device for measuring the microwave power produced by a microwave oven so as to determine whether the oven is producing its rated or set power, to prevent inadvertent undercooking of food, includes a calorimeter employing tap water as a working medium and a thermometer that can be set initially to read zero for any initial temperature of the working medium. In accordance with the invention, an enclosure containing a quantity of gaseous neon is connected to the calorimeter, and the gaseous neon glows only when radiation is present. The actual irradiation time, which may be less than the set cooking time due to start-up delay, may be accurately determined by timing the duration of the neon glow as observed through the window of the oven.