| 摘要 |
An apparatus and method for controlling the operating temperatures and differential temperature of a curie effect temperature sensing switch is disclosed. The temperature switch is adapted to provide temperature control of a cold plate in a reagent refrigerator. The temperature switch activates cold plate cooling devices when the cold plate temperature is above a first operating temperature and deactivates the cold plate cooling devices when the cold plate temperature is below a second operating temperature. An electromagnet is fixed external of and relative to the temperature switch so that the strength of the external magnetic field sets the operating temperatures of the temperature switch. A potentiometer is used to incrementally vary the current supplied to the electromagnet to thereby incrementally adjust the strength of the external magnetic field and the operating temperatures. A microprocessor may be provided to adjust the voltage supply of the potentiometer, which allows remote control of the operating temperatures. A second potentiometer is connected to the electromagnet so that it incrementally adjusts the current passed to the electromagnet as a function of whether the temperature switch is open or closed. Incremental adjustment of the second potentiometer provides incremental adjustment of the temperature differential. A monitor provides a warning signal if the temperature switch does not open and close within a predetermined time interval.
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