Method and apparatus for proving electronic gas meters

• US 4,953,386 A
• Filed: 11/13/1989
• Issued: 09/04/1990
• Est. Priority Date: 10/11/1988
• Status: Expired due to Term

• Current Assignee: Gas Research Institute (GTI Energy)
• Original Assignee: Gas Research Institute (GTI Energy)
• Inventors: Lyden, Daniel T., Gilman, Robert E., Woessner, Michael A., Pearman, Arthur N. J., Hunter, Gerald D.
• Primary Examiner(s): Noland, Tom
• Application Number:
  US07/434,595
• Time in Patent Office: 295 Days
• Field of Search: 73/3, 364/510
• US Class Current: 73/1.27
• CPC Class Codes: G01F 25/10 of flowmeters
• CPC Class Codes: G01F 25/15 specially adapted for gas meters G01F25/11 - G01F25/14, G01F25/17 take precedence

Abstract

A method and apparatus for proving an electronic gas meter and the like that includes counting the number of pulses provided by an encoder associated with a bell prover to define a volume of test fluid which is supplied to the meter under test, enalbing the meter to measure the volumetric fluid flow rate and integrating the volumetric flow rate of test fluid measured by the gas meter during the test, and data representing the actual volume of test fluid supplied to the meter under test to determine the percent proof or accuracy of the meter.

Claims

1. A method for proof testing of an electronic gaseous fluid flow meter including a solid state fluid flow sensor and a signal processing circuit, the flow sensor of the meter providing a signal output indicative of fluid flow measured thereby, the signal processing circuit of the meter including timing means for generating periodically recurring timing signals defining sampling intervals for the meter, sampling means which samples the signal output of the fluid flow sensor during the sampling intervals to obtain flow measurement data representing the volume of fluid that has been passed through the meter, and memory means for storing the flow measurement data, the method comprising the steps of:

supplying to the meter under test a volume of a gaseous test fluid using a volume measurement standard apparatus;

generating an enabling signal for the signal processing circuit of the meter under test to cause the sampling means to start sampling the signal output of the fluid flow sensor during sampling intervals defined by the timing means and accumulating in the memory means of the meter measurement data representing the volume of test fluid measured by the meter in response to fluid flow through the meter during the sampling intervals;

generating a plurality of electrical pulses, the number of pulses generated being indicative of the actual volume of the test fluid which is passed through the meter during the test;

causing the signal processing circuit of the meter to enable a pulse counter to start registering the electrical pulses at the start of the first sampling interval during which the signal processing circuit of the meters starts sampling the signal output of the fluid flow sensor;

monitoring the pulse counter to determine when a preselected number of pulses has been registered by the pulse counter, the preselected number of pulses being indicative of a preselected volume of test fluid having been passed through the meter under test;

causing the meter to stop conducting fluid flow measurements when said preselected number of pulses has been registered by the pulse counter;

causing the signal processing circuit of the meter to disable the pulse counter at the start of the first sampling interval after the pulse counter registers said preselected number of pulses to stop the pulse counter from registering further pulses; and

correlating measurement data stored in the memory means of the meter indicative of the volume of test fluid which is measured by the meter during the test with data representing the count registered by the pulse counter indicative of the actual volume of the test fluid passed through the meter during the test for proving the operation of the meter.

2. A method according to claim 1, which includes delaying the enabling of the signal processing circuit of the meter and the registering of the pulse count until the rate of fluid flow to the meter becomes substantially constant prior to measurement of the fluid flow volume through the meter.

3. A method according to claim 2, wherein delaying the enabling of the signal processing circuit of the meter includes generating a plurality of pulses registering the plurality of pulses for enabling the meter in a pulse counter, and generating an enabling signal when said pulse counter has registered a count corresponding to the number of said plurality of pulses.

4. A method according to claim 3, wherein the volume measurement standard apparatus comprises a bell prover including a test bell, and wherein measuring the volume of the test fluid which passes through the meter under test includes monitoring the position of the test bell using a position encoder means, the encoder means generating said electrical pulses to indicate the position of the bell as it moves from an initial position to a further position in measuring the actual volume of the test fluid supplied to the meter.

5. A method for proof testing of an electronic gaseous fluid flow meter of the type including a solid state fluid flow sensor and a signal processing circuit, the flow sensor of the meter providing a signal output indicative of fluid flow measured thereby, the signal processing circuit of the meter including timing means for generating periodically recurring timing signals defining sampling intervals for the meter, sampling means which samples the signal output of the fluid flow sensor during the sampling intervals to obtain flow measurement data representing the volume of fluid that has been passed through the meter, and memory means for storing the flow measurement data, the method comprising the steps of:

supplying to the meter under test a volume of a test fluid using a bell prover apparatus including a test bell which moves between first and second positions in supplying a volume of test fluid to the meter under test;

generating an enabling signal for the signal processing circuit of the meter to cause the sampling means to start sampling the signal output of the fluid flow sensor during sampling intervals defined by the timing means and accumulating in the memory means of the meter data representing the meter volume flow measurement data obtained for the meter during the sampling intervals;

generating a plurality of electrical pulses, the number of pulses generated being indicative of the actual volume of the test fluid supplied to the meter by the test bell during movement of the test bell between positions;

causing the signal processing circuit of the meter to enable a pulse counter to start registering the electrical pulses at the start of the first sampling interval during which the signal processing circuit starts sampling the signal output or the fluid flow sensor;

monitoring the pulse counter to determine when the pulse counter has registered a preselected number of pulses, the preselected number of pulses being indicative of a preselected volume of test fluid having been passed through the meter under test;

disabling the signal processing circuit of the meter to cause the sampling means to stop sampling the signal output of the fluid flow sensor when said preselected number of pulses has been registered by the pulse counter;

causing the signal processing circuit of the meter to disable the pulse counter at the start of the first sampling interval occurring after the pulse counter registers said preselected number of pulses to stop the pulse counter from registering further pulses,

deriving from the pulse count registered by the pulse counter volume flow data representing the actual volume of test fluid which is passed through the meter during the test; and

correlating the actual volume flow data derived from the pulse counter with the meter volume flow measurement data stored in the memory means of the meter in proving the operation of the meter.

6. A method according to claim 5, which includes delaying the enabling of the signal processing circuit for a time interval following movement of the test bell away from said first position.

7. A method according to claim 6, wherein generating the electrical pulses includes using an encoder means to monitor the displacement of the test bell from its first position to its second position and wherein delaying the enabling of the signal processing circuit includes registering in a further pulse counter electrical pulses generated by said encoder means and generating a signal for enabling the signal processing circuit when a preselected number of pulses have been registered.

8. Apparatus for proof testing of an electronic gaseous fluid flow meter including a solid state fluid flow sensor and a signal processing circuit, the flow sensor of the meter providing a signal output indicative of fluid flow measured thereby, the signal processing circuit of the meter including timing means for generating periodically recurring timing signals defining sampling intervals for the meter, sampling means which samples the signal output of the fluid flow sensor during the sampling intervals to obtain flow measurement data representing the volume of fluid that has been passed through the meter, and memory means for storing the flow measurement data, the apparatus comprising:

means including a volume measurement standard apparatus for supplying to the meter under test a volume of a gaseous test fluid;

control means for generating an enabling signal for enabling the signal processing circuit of the meter under test to cause the sampling means to start sampling the signal output of the fluid flow sensor during sampling intervals defined by the timing means and accumulating in the memory means volume flow measurement data representing the volume of test fluid measured by the meter in response to fluid flow through the meter;

pulse generating means associated with said volume measurement standard apparatus for generating a plurality of electrical pulses, the number of pulses generated being indicative of the actual volume of the test fluid which is passed through the meter during a test;

pulse counting means coupled to said pulse generating means and enabled by the signal processing means of the meter in response to the generation of the timing signal which defines the first sampling interval for the processing circuit, to start registering the electrical pulses generated by said pulse generating means;

said control means being coupled to said pulse counting means and responding to said pulse counting means to terminate said enabling signal to disable the signal processing circuit of the meter to thereby cause the meter to stop conducting fluid flow measurements when the pulse counting means has registered a preselected number of pulses indicative of a preselected volume of test fluid having been passed through the meter under test; and

the signal processing circuit of the meter responsively disabling said pulse counting means at the start of the first sampling interval after said pulse counting means registers said preselected number of pulses to stop said pulse counting means from registering further pulses;

said control means correlating measurement data stored in the memory means of the meter indicative of the volume of test fluid which is measured by the meter during said test with data representing the count registered by said pulse counting means indicative of the actual volume of the test fluid passed through the meter for proving the operation of the meter.

9. Apparatus according to claim 8, which includes delay means for delaying the enabling of the signal processing circuit of the meter for a time sufficient to allow the rate of fluid flow to the meter to become substantially constant prior to measurement of the fluid flow volume through the meter.

10. Apparatus according to claim 9, wherein said delay means includes a further pulse counting means coupled to said pulse generating means for registering pulses generated by said pulse generating means and means for generating said enabling signal when said further pulse counting means has registered a given number of pulses.

11. Apparatus according to claim 8, wherein said volume measurement standard apparatus comprises a bell prover mean including a test bell, and wherein said pulse generating means comprises encoder means, said encoder means being coupled to said test bell for generating said electrical pulses to indicate the position of said bell as it moves from an initial position to a further position in measuring the actual volume of the test fluid supplied to the meter.

12. Apparatus for use in proving an electronic gaseous fluid flow meter of the type including a solid state fluid flow sensor and a signal processing circuit, the flow sensor of the meter providing a signal output indicative of fluid flow measured thereby, the signal processing circuit of the meter including timing means for generating periodically recurring timing signals defining sampling intervals for the meter, sampling means which samples the signal output of the fluid flow sensor during the sampling intervals to obtain flow measurement data representing the volume of fluid that has passed through the meter, and memory means for storing the flow measurement data, the apparatus comprising:

a bell prover means having a test bell which moves between first and second positions in supplying a volume of test fluid to the meter under test;

encoder means associated with the test bell for generating electrical pulses, the number of pulses generated being indicative of the volume of test fluid supplied to the meter under test by the test bell as the test bell moves between the first and second positions during a test;

pulse counting means coupled to said encoder means and operable when enabled to register the pulses generated by the encoder means;

control means for generating an enabling signal for enabling said signal processing circuit of the meter to cause the sampling means to start sampling the output of said fluid flow sensor during sampling intervals defined by the timing means as the test bell moves between said first and second positions to obtain flow measurement data representing the volume of fluid flow measured by the meter during the test and to accumulate the flow measurement data in the memory means;

said signal processing circuit of the meter responding to said enabling signal to enable said pulse counting means at the beginning of the first sampling interval to start registering the pulses generated by said encoder means, said control means being responsive to said pulse counting means registering a preselected number of pulses to terminate said enabling signal to disable the signal processing circuit of the meter and thereby cause said signal processing circuit of the meter to stop sampling the signal output of said fluid flow sensor and to disable said pulse counting means at the start of the first sampling interval after said pulse counting means registers said preselected number of pulses, whereby the pulse count registered by said pulse counting means is indicative of the actual volume of fluid flow through the meter during the sampling intervals that the signal processing circuit of the meter was enabled to sample the signal output of the fluid flow sensor;

said control means correlating the measurement data stored in the memory means of the meter which is indicative of the volume of test fluid which is measured by the meter during the sampling intervals with data representing the count registered by the pulse counting means which is indicative of the actual volume of the test fluid passed through the meter for proving the operation of the meter.