Apparatus and method for determining the measurement accuracy of electronic gas meters

Claim 1

An apparatus for automatically determining the measurement accuracy of an uncalibrated field fluid flow meter by comparing its fluid flow volume measurement, V f , to a fluid flow volume measurement, V m , of a master meter of known accuracy, the apparatus comprising: a blower operably coupled to the field and master meters for passing a common fluid stream through the field and master meters at a predetermined flow rate until a predetermined volume of fluid has been registered by the field meter; first measurement signalling means coupled to said field and master meters for generating data representing the fluid volume registered by each of said meters; second measurement signalling means operatively coupled to the fluid stream for generating data representing a first input temperature, T 1 , and a first input pressure, P 1 , of the common fluid stream to the field meter and a second input temperature, T 2 , and a second input pressure, P 2 , of the common fluid stream to the master meter; a computer including an input for operator interface with said apparatus and for automatically controlling the predetermined flow rate and calculating average pressures and temperatures, P 1avg , P 2avg , T 1avg , and T 2avg and a percent field meter accuracy according to the equation: % Accuracy=V.sub.f /V.sub.m ·P.sub.1avg /P.sub.2avg ·T.sub.2avg /T.sub.1avg 100; said computer presenting graphic display to prompt said operator through a controlled test of the field meter; a controller coupled to the computer for sending data to and receiving commands from said computer and for configuring a sequential control of said test of the field meter according to parameters designated by the computer and selected by the operator according to said graphic display prompts; said blower being-operably coupled to the controller for forcing fluid through both the field and master meters as instructed by the controller; a memory in the computer for storing a plurality of preset flow rates selectable by said operator according to said graphic display prompts and storing the calculated pressures, temperatures, and accuracy of the related field meter; the controller being coupled to the first and second measurement signalling means; the controller including a microprocessor for gathering data from the first and second measurement signalling means and for providing temperature, pressure, and fluid volume values to the computer; and display means for displaying the calculated pressures, temperatures, and accuracy of the tested field meter.

Claim 2

An apparatus for automatically determining the measurement accuracy of an uncalibrated field fluid flow meter by comparing its fluid flow volume measurement, V f , to a fluid flow volume measurement, V m , of a master meter of known accuracy, the apparatus comprising: a blower operably coupled to the field and master meters for passing a common fluid stream through the field and master meters at a predetermined flow rate until a predetermined volume of fluid has been registered by the field meter; first measurement signalling means coupled to said field and master meters for generating data representing the fluid volume registered by each of said meters; second measurement signalling means operatively coupled to the fluid stream for generating data representing a first input temperature, T 1 , and a first input pressure, P 1 , of the common fluid stream to the field meter and a second input temperature, T 2 , and a second input pressure, P 2 , of the common fluid stream to the master meter; a computer including an input for operator interface with said apparatus and for automatically controlling the predetermined flow rate and calculating average pressures and temperatures, P 1avg , P 2avg , T 1avg , and T 2avg and a percent field meter accuracy according to the equation: % Accuracy=V.sub.f /V.sub.m ·P.sub.1avg /P.sub.2avg ·T.sub.2avg /T.sub.1avg 100; said computer presenting graphic display to prompt said operator through a controlled test of the field meter; a controller coupled to the computer for sending data to and receiving commands from said computer and for configuring a sequential control of said test of the field meter according to parameters designated by the computer and selected by the operator according to said graphic display prompts; said blower being-operably coupled to the controller for forcing fluid through both the field and master meters as instructed by the controller; a memory in the computer for storing a plurality of preset flow rates selectable by said operator according to said graphic display prompts and storing the calculated pressures, temperatures, and accuracy of the related field meter; the controller being coupled to the first and second measurement signalling means; the controller including a microprocessor for gathering data from the first and second measurement signalling means and for providing temperature, pressure, and fluid volume values to the computer; and display means for displaying the calculated pressures, temperatures, and accuracy of the tested field meter.

Claim 8

A method for automatically determining the measurement accuracy of an uncalibrated field fluid flow meter, the method comprising the steps of: (a) operably connecting a blower to the field meter and a master meter for passing a common fluid stream through both of the meters at a predetermined fluid flow rate for a predetermined fluid flow volume indicated by the field meter; (b) operably coupling a controller to the blower, field meter, master meter, and a computer; (c) providing graphic displays with said computer to prompt an operator through a controlled test of the field meter, said selected prompts causing the controller to adjust the blower to obtain a predetermined fluid flow rate through the field and master meters in response to commands from the computer as selected by the operator according to said graphic display prompts; (d) gathering data with the controller representing a first input temperature, T 1 , and a first input pressure, P 1 , of the common fluid stream to the field meter and a second input temperature, T 2 , and a second input pressure, P 3 , of the common fluid stream of the master meter, and data representing the volume of fluid passed by each of the field meter and master meter; (e) freezing the master meter volume data when the field meter indicates a predetermined volume has been passed; (f) storing said frozen master meter volume data for subsequent use by said computer; and (g) calculating proof, accuracy, and error values of the field meter relative to the master meter with the computer from the gathered data and storing the calculated values in a memory portion of the computer.

Claim 9

A method for automatically determining the measurement accuracy of an uncalibrated field fluid flow meter, the method comprising the steps of: (a) operably connecting a blower to the field meter and a master meter for passing a common fluid stream through both of the meters at a predetermined fluid flow rate for a predetermined fluid flow volume indicated by the field meter; (b) operably coupling a controller to the blower, field meter, master meter, and a computer; (c) providing graphic displays with said computer to prompt an operator through a controlled test of the field meter, said selected prompts causing the controller to adjust the blower to obtain a predetermined fluid flow rate through the field and master meters in response to commands from the computer as selected by the operator according to said graphic display prompts; (d) gathering data with the controller representing a first input temperature, T 1 , and a first input pressure, P 1 , of the common fluid stream to the field meter and a second input temperature, T 2 , and a second input pressure, P 3 , of the common fluid stream of the master meter, and data representing the volume of fluid passed by each of the field meter and master meter; (e) freezing the master meter volume data when the field meter indicates a predetermined volume has been passed; (f) storing said frozen master meter volume data for subsequent use by said computer; and (g) calculating proof, accuracy, and error values of the field meter relative to the master meter with the computer from the gathered data and storing the calculated values in a memory portion of the computer.