Patent ID: 8021125

Claim:
A hermetic compressor system comprising: a housing accommodating a motor and a compressing mechanism driven by the motor; refrigerating machine oil, pooled in the housing, for lubricating the compressing mechanism; refrigerant gas sealed into the housing and acting as a refrigerant in a refrigerating cycle; an oil surface sensor including a thermistor having a length; an insulator; a holder for holding the oil surface sensor, the holder including a first portion mounted to an external surface of a side wall of the compressing mechanism and a second portion extending outwardly from the external surface of the side wall of the compressing mechanism, the second portion of the holder extending around the insulator; a comparator which compares a stored temperature of the thermistor and a stored rate of change in temperature of the thermistor after energizing the thermistor to a subsequent temperature of the thermistor and a subsequent rate of change in temperature of the thermistor; and a processor which determines what portion of the length of the thermistor extends into the refrigerating machine oil based on the compared results.