Refrigerant measuring and warning device and sensing element thereof

Abstract

A refrigerant measuring and warning device includes a casing, at least one sensing element, and a detection circuit. The casing forms connectors, which are connected together by a conduit, to selectively connect to sources of refrigerant to be detected. The sensing element has an enclosure forming a connector at an end for connection with the conduit and an interior chamber communicating the connector via a pressure-dropping necked passage, a pressure detection chip and a thermocouple arranged at a top of the chamber for detecting pressure and temperature of the refrigerant to be detected. The detection circuit is housed in the casing and stores multiple sets of reference temperature and pressure for different type of refrigerants for comparison with the detected pressure and temperature, both data being displayed on a display device for visual observation and comparison. The detection circuit receives settings of alarm thresholds for the detected pressure and temperature via a keypad whereby a warning unit may issue a warning sound or voice alarm when the detected pressure and temperature reach/exceed the thresholds.

1 . A refrigerant measuring and warning device comprising:
 a casing forming connectors adapted to selectively connect sources of refrigerant to be detected, a connection conduit connecting among the connectors;   at least one sensing element connected to the connection conduit inside the casing to detect pressure and temperature of refrigerant from the refrigerant source and supply detected signals of the pressure and temperature; and   a detection circuit comprising a microprocessor, a memory, a display device, a keypad, a warning unit, and a power supply device, the microprocessor having a built-in input signal conversion circuit, which is coupled to the sensing element to receive and convert the detected pressure and temperature signals into digital data that is applied to the microprocessor, the memory storing multiple sets of reference refrigerant pressure and temperature, the keypad being operable to enter selection instruction and warning instruction of pressure and temperature to the microprocessor and the display device being operable to show the detected refrigerant pressure and temperature and the reference pressure and temperature on the display for comparison, the warning unit being coupled to the microprocessor to issue an alarm when the detected refrigerant pressure and temperature reach/exceed preset warning thresholds, the power supply device powering the microprocessor, the memory, the display device, the keypad, and the warning unit.   
   
   
       2 . The device as claimed in  claim 1 , wherein the input signal conversion circuit of the detection circuit comprises a plurality of amplifiers, a voltage level transformation circuit, and an analog-to-digital converter. 
   
   
       3 . The device as claimed in  claim 2 , wherein the input signal conversion circuit of the detection circuit comprises a circuit comprised of transistors and/or thyristors. 
   
   
       4 . The device as claimed in  claim 1 , wherein the display device comprises an LCD drive circuit, a backlight drive circuit, and a display panel. 
   
   
       5 . The device as claimed in  claim 1 , wherein the warning unit is connected to an alarm device. 
   
   
       6 . The device as claimed in  claim 5 , wherein the alarm device comprises a buzzer. 
   
   
       7 . The device as claimed in  claim 1 , wherein the power supply device comprises a direct-current battery set. 
   
   
       8 . A refrigerant sensing element comprising:
 an enclosure, having an end forming a connector adapted to connect to a supply of refrigerant to be detected, the enclosure forming an interior chamber, which communicates the connector with a pressure-dropping necked passage to convey the refrigerant to be detected, in a pressure dropped condition, into the chamber;   a pressure detection chip, arranged at a top of the chamber to detect pressure of refrigerant supplied into the chamber of the enclosure; and   a thermocouple, arranged at the top of the chamber to detect temperature of the refrigerant supplied into the chamber of the enclosure.   
   
   
       9 . The sensing element as claimed in  claim 8 , wherein the enclosure has an end forming an inner-threaded opening in which a thread is formed. 
   
   
       10 . The sensing element as claimed in  claim 9  further comprising a threaded closing member engaging and retained in the inner-threaded opening. 
   
   
       11 . The sensing element as claimed in  claim 8 , wherein the pressure detection circuit and the thermocouple are mounted on a control circuit board. 
   
   
       12 . The sensing element as claimed in  claim 8 , wherein the pressure detection chip has a detection end and terminals on the opposite end. 
   
   
       13 . The sensing element as claimed in  claim 8 , wherein the pressure detection chip is connected to constant current source. 
   
   
       14 . The sensing element as claimed in  claim 8 , wherein the thermocouple has terminals.