Electronic instrument for refrigerant recovery machine

Abstract

Used in a refrigerant recovery machine having a refrigerant input pipe and a refrigerant output pipe, an electronic instrument is disclosed to include a control unit, a LCD device controllable by the control unit to display the operation status of the refrigerant recovery machine, and a pressure sensor unit having an input pipe pressure sensor and an output pipe pressure sensor for detecting the pressure in the input pipe and the pressure in the output pipe and transmitting the respective detected pressure values to the control unit for comparison with a pre-set pressure threshold limit value so that the control unit controls the operation of the refrigerant recovery machine subject to the comparison results.

1 . An electronic instrument used in a refrigerant recovery machine comprising a refrigerant pipe system, a compressor pipe line and a condenser pipe line, said refrigerant pipe system having an input pipe and an output pipe, the electronic instrument comprising:
 a control unit for controlling the operation of said refrigerant recovery machine, said control unit comprising a microprocessor having set therein at least one pressure threshold limit value;   a liquid crystal display device electrically connected to said control unit and controllable by said control unit to display status of said refrigerant recovery machine; and   a pressure sensor unit electrically connected to said control unit, said pressure sensor unit comprising an input pipe pressure sensor adapted to detect the pressure in said input pipe and to transmit the detected temperature value to said control unit for comparison with one said pressure threshold limit value and an output pipe pressure sensor adapted to detect the pressure in said input pipe and to transmit the detected temperature value to said control unit for comparison with one said pressure threshold limit value.   
     
     
         2 . The electronic instrument as claimed in  claim 1 , wherein said at least one pressure threshold limit value comprises a high-pressure threshold limit value and a negative pressure threshold limit value. 
     
     
         3 . The electronic instrument as claimed in  claim 1 , further comprising a temperature sensor unit electrically connected to said microprocessor of said control unit, said temperature sensor unit comprising an input pipe temperature sensor adapted to detect the temperature in said input pipe and to transmit the detected temperature value to said microprocessor for comparison with a predetermined temperature threshold limit value set in said microprocessor, an output pipe temperature sensor adapted to detect the temperature in said output pipe and to transmit the detected temperature value to said microprocessor for comparison with said predetermined temperature threshold limit value, a compressor pipe line temperature sensor adapted to detect the temperature in said compressor pipe line and to transmit the detected temperature value to said microprocessor for comparison with said predetermined temperature threshold limit value and a condenser pipe line temperature sensor adapted to detect the temperature in said condenser pipe line and to transmit the detected temperature value to said microprocessor for comparison with said predetermined temperature threshold limit value.