Patent ID: 7607823

Claim:
A fluid leak detector comprising: a sensing circuit including a first thermistor device adapted to detect a fluid leak upon contact with a liquid, and, a second thermistor device functioning as a reference device; means for driving said first and second thermistor devices with a current such that both said first and second thermistor devices operate in self-heated mode at a temperature above an ambient temperature; and, a control system for controlling said driving means so as to maintain a constant application of power through both said first and second thermistor devices in response to a voltage Vs monitored at a reference point in a portion of said sensing circuit including said second thermistor device, said control system including means for monitoring the voltage Vs′ at a reference point in a portion of said sensing circuit including said first thermistor device; and, a comparing means for comparing the voltage Vs′ at a reference point in said sensing circuit including said first thermistor device with the voltage Vs at a reference point in said sensing circuit including said second thermistor device and determining a fluid leak condition on the basis of a comparison result irregardless of said ambient temperature.