Apparatus and method for proving gas meters and improved sensor therefor

A method for testing the accuracy of a diaphragm gas meter comprising the following steps:

• placing an external magnetic sensor in proximity to the oscillating diaphragm of a gas meter under test, each of said diaphragm oscillations corresponding to the passage through said gas meter of a quantity of test gas, said periodic oscillation of the diaphragm resulting in the activation of said magnetic sensor;
• sensing an electrical signal generated by the activation of said sensor, said signal corresponding to a an amount of gas passing through said meter;
• measuring the amount of gas passing through said meter using a standard;
• and
• comparing the amount of gas measured by the standard with the amount of test gas passing through said meter as sensed by the activation of said sensor in order to determine the accuracy of said meter.

Apparatus for proving a test meter comprising:

• means for supplying a test gas to a diaphragm gas meter under test;
• encoder means for determining the amount of test gas supplied from said supplying means;
• valve means for regulating, the flow of gas from said supply means to said diaphragm gas meter under test;
• a magnetic sensor placed in proximity to the oscillating diaphragm of said gas meter under test, each of said oscillations corresponding to a fixed quantity of gas passing through said meter, said oscillating diaphragm periodically interfering with said magnetic sensor thereby resulting in the activation of said sensor, each of said activations corresponding to the passage of a fixed quantity of test gas through said meter;
• electronic port means which activates upon the activation of said sensor;
• and
• processor means for comparing the quantity of gas sensed by said encoder with the quantity of gas sensed by said magnetic sensor.

A method for testing the accuracy of a diaphragm gas meter comprising the following steps:

• retaining a plurality of coplanar metallic reeds in a non-contacting relationship with a magnetic field;
• placing said magnetically non-contacting reeds in proximity to the oscillating diaphragm of a gas meter under test, each of said diaphragm oscillations corresponding to the passage through said gas meter of a quantity of test gas, said periodic oscillation of the diaphragm interfering with said magnetic field, thereby resulting in the contact of the reeds;
• sensing an electrical signal generated by the contact of said reeds, said signal corresponding to an amount of gas passing through said meter;
• measuring the amount of gas passing through said meter using a standard;
• and
• comparing the amount of gas measured by the standard with the amount of gas passing through said test meter as sensed upon the contact of said reeds in order to determine the accuracy of said meter.