Pressure measurement system for refrigeration system

• US 5,311,745 A
• Filed: 01/27/1993
• Issued: 05/17/1994
• Est. Priority Date: 01/27/1993
• Status: Expired due to Term

• Current Assignee: Digi-Cool Industries Limited
• Original Assignee: Digi-Cool Industries Limited
• Inventors: Varelas, Oreste B. N., Lockhart, Douglas L.
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US08/009,671
• Time in Patent Office: 475 Days
• Field of Search: 62/125, 62/126, 62/127, 62/129, 62/149, 62/292, 62/298
• US Class Current: 62/127
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: G01L 19/083 electrical

Abstract

A pressure measuring system for a refrigeration system, such as a refrigeration system used in a commercial air conditioning system, comprises a converter (42) for converting a pressure being measured into a digital signal representing the measured pressure and a processor (54) for calculating a corresponding boiling point temperature for a selected refrigerant at the measured temperature. The system also includes a selector for selectively inputting the boiling point temperature-pressure relationship or coefficient of a selected refrigerant into the processor, as well as a display (60) for displaying the measured pressure and the calculated boiling point temperature.

Claims

1. A pressure measuring system for a refrigeration system, comprising:

conversion means for converting a pressure being measured into a digital signal representing said measured pressure;

processing means for calculating a corresponding boiling point temperature for a selected refrigerant at said measured pressure;

refrigerant selection means for selectively inputting into said processing means the boiling point temperature-pressure relationship or coefficient of said selected refrigerant;

display means for displaying said measured pressure and the calculated boiling point temperature;

wherein said processing means further comprises means for continuously performing successive calculations as said measured pressure varies with time and update means for updating the pressure and boiling point temperature values displayed by said display means at predetermined intervals; and

control means for activating said display means to indicate the direction of a pressure change, upward or downward, during said predetermined time intervals in between said updating of the pressure and temperature values.

2. The pressure measuring system according to claim 1, wherein said refrigerant selection means comprises a memory for storing the boiling point temperature-pressure relationship of a plurality of different refrigerants.

3. The pressure measuring system according to claim 1, wherein said refrigerant selection means comprises an interface for receiving a plug-in memory chip containing the boiling point temperature-pressure relationship of a particular refrigerant.

4. The pressure measuring system according to claim 1, wherein said predetermined time intervals is selectable from the group of intervals consisting of one-second and five-second intervals.

5. The pressure measuring system according to claim 1, wherein said conversion means comprises a transducer for converting said measured pressure into an analog electric signal and an analog-digital converter for converting the analog signal to a digital signal for inputting into said processing means.

6. The pressure measuring system according to claim 5, comprising a pair of said transducers for connection to the high and low pressure sides of a refrigeration system, respectively.