Inventors:
Robert E. Dawley - Natick MA
International Classification:
F25B 4900, F25B 2102, G05D 2330
Abstract:
A temperature control system including an enclosure defining a zone to be temperature controlled, a primary temperature conditioner for controlling ambient temperature within the zone, a temperature sensing mechanism for producing temperature signals dependent on localized temperature within the zone, a controller for controlling the primary temperature conditioner in response to the temperature signal, an error detector for monitoring the temperature signal and producing error signals in response to predetermined abnormal output conditions thereof, an auxiliary temperature conditioner disposed in close heat transfer relationship with the sensing mechanism and selectively energizable during test periods to substantially alter the localized temperatures sensed by the sensing mechanism without substantially changing the ambient temperature within the zone, and a fault detector for producing fault signals in response to given defective output conditions of the temperature signal during the test periods.