water mist discharged into the cabinet air circulation system an electronic system combines the input from the sensor the temperature inputs and the humidity percentage setting to regulate the timing and duration of the water mist discharge thereby allowing to adjust percentage of humidity in heated holding cabinets the sensor is a capacitor comprising two plates in close proximity but insulated from each other the electrical output of the capacitor is sensitive to moisture on the surfaces between the plates by cooling one plate until it reaches its dew point the signal is detected and received by the electronic system cooling of the capacitor plate is accomplished by means of a thermoelectric cooler when cabinet humidity falls below a predetermined threshold value and a corresponding change in capacitance of the capacitive sensor is detected the humidity control system turns on a water mister to spray water into cabinet air flow until a desired relative humidity level is reached in the heated cabinet application_number US 51609795 A description the present invention is a humidity control system described with respect to heated holding cabinets in the following description numerous specific details are set forth to provide a more thorough description of the present invention it will be apparent however to one skilled in the art that the present invention may be practiced without these specific details in other instances well known features have not been described in detail so as not to obscure the present invention heated holding cabinets are commonly used to provide transportation or storage means for food to maintain food in a heated or warm condition for an extended period of time the heated holding cabinets are usually equipped with a temperature control system to keep the cabinet temperature optimal for stored.