Methods and apparatus for proving gas meters

In apparatus for use in proving a positive displacement, diaphragm-operated gas meter having metering mechanism comprising a fluid pressure transducer responsive to the test gas flowing through the meter to sense a train of pressure waves which occur and reoccur in each cycle of operations of the metering mechanism in a test run to produce signals of various voltages, including one or more characteristic peak voltage signal in each train of signals depending on the form of the meter being tested;

• means for amplifying the signals of each train of signals issuing from said transducer;
• means for detecting and amplifying said characteristic peak voltage signals;
• means for shaping said signals;
• and counting means for counting one of said characteristic peak voltage signals from each of said train of signals received in each cycle of operations of the meter.

In apparatus for proving a positive displacement, diaphragm-operated fluid meter having metering mechanism, and inlet and outlet ports comprising a fluid pressure transducer in communication with said inlet and outlet ports of the meter and responsive to the pressure fluctuations which occur and reoccur in each cycle of operations of said metering mechanism and convert said pressure fluctuations to signals of varying voltage;

• means for amplifying said signals;
• means for amplifying and shaping a series of peak waveforms occurring in each cycle of operations of said metering mechanism, including at least one peak voltage waveform;
• a cycle counter;
• an analog comparator to pass to said cycle counter one of said peak waveform signals of said series of waveform signals occurring in each cycle of operation of said metering mechanism;
• a test gas volume encoder for producing a series of signals, one for each predetermined volume of test gas passing through the meter;
• a digital comparator;
• a counter and totalizer;
• and means, including said digital comparator, for passing one of said signals from the cycle counter to said counter and totalizer in each cycle of operation of the metering mechanism of the meter.

In apparatus for use in proving a positive displacement, diaphragm-operated gas meter having adjustable index-operating mechanism comprising a gas pressure transducer in communication with the interior of said meter and responsive to pressure fluctuations which occur and reoccur in each cycle of operations of the meter and converting said fluctuations to signals of varying voltages;

• a first differential amplifier connected to said transducer to increase the amplitude of said signals;
• a first peak detector to which amplified signals are passed;
• a first attenuator to reduce the amplitude of said signals coming from said first peak detector;
• a second differential amplifier;
• means for feeding the signals passing from said first differential amplifier and signals passing from said first attenuator to said second differential amplifier;
• a second peak detector;
• means for feeding signals passing from said second differential amplifier to said second peak detector;
• a second attenuator;
• means for feeding signals passing from the second peak detector to said second attenuator;
• an analog comparator;
• means for feeding signals passing from said second attenuator and from said second differential amplifier to said analog comparator;
• a revolution counter;
• means for conducting signals from said analog comparator to said cycle counter;
• a volume encoder;
• a digital comparator;
• means for feeding signals from said volume encoder to said digital comparator;
• a counter and totalizer;
• and means for feeding signals from said digital comparator to said revolution counter to enable the latter to feed a signal to said counter and totalizer.

The herein described method of proving a positive displacement, a diaphragm-operated gas meter having metering mechanism and a test bell;

• means communicating with the interior of the meter including means connected to said inlet and outlet ports for sensing the fluctuations of pressure of the test gas occurring in the meter in a cycle of operation of the meter, and reoccurring during each cycle of operations of said meter, thereby producing a train of varying voltages which repeat in each cycle of operations;
• amplifying said train of signals;
• detecting and holding a peak signal or peak signals occurring in each signal train;
• simultaneously measuring the volume of test gas passing through the meter and relating said volume of test gas to a cycle or cycles of operation of the meter;
• and converting such relationship to an indication of the degree proof.