Abstract: A circuit arrangement is provided to mitigate the parasitic capacitance that typically is associated with solid state switches which are designed to carry high current magnitudes. By disposing a capacitive component in series with a power switch which, in turn, is connected in series with an inductive component, the overall capacitance of the switch and capacitive component are significantly reduced. In a preferred embodiment of the present invention, the capacitive component is a diode with a voltage potential provided at the cathode of the diode so that the parasitic capacitance of the diode can be varied to tune the total circuit for the purpose of achieving a specific resonant frequency.

Abstract: A method and apparatus for the calibration of electronic gas meters and the like includes subjecting the meter under test to test fluid at a series of differing known volumetric flow rates, determining the meter response using a bell prover to determine volume flow rate, and using data obtained from the series of tests in the calculation of calibration data which is stored in the memory of the electronic meter for use in subsequent volumetric flow measurement by the meter.

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.

Abstract: A method and apparatus for proving an electronic gas meter at low flow rates includes comparing the rate of descent of the test bell of a bell prover with the instantaneous flow rate measured by a fluid flow measuring circuit for the meter, the rate of descent of the test bell being determined by counting the number of clock pulses which are generated by a clock pulse generator of the test circuitry signal to provide a measure of actual volume flow rate for comparison with the measured volume flow rate obtained from the electronic gas meter.

Abstract: An electronic compact gas meter includes a solid state flow sensor for sensing gas flow rate, data acquisition circuits including an analog-to-digital converter coupled to the sensor for controlling same and providing an output indicative of gas flow, and a digital data processor for receiving the gas flow information from the analog-to-digital converter, processing the information and registering the volumetric gas flow reading at the meter and/or transmitting the volume flow information via RF or telephone communication lines to a remote location.

Abstract: The invention relates to a coefficient of performance deviation meter for vapor compression type refrigeration systems. The measurement of the coefficient of performance of a mechanical vapor compression refrigeration system requires that the two parameters be known which are the input power and the heat absorbed or, conversely, the input power and the heat rejected. Manufacturers of vapor compression machines publish performance data on the power used versus the cooling effect at various condenser water supply temperature (Tcws) and various evaporator chilled water supply temperature (Tchws). These data can be used to calculate specific coefficients of performance (COPs) at various Tcws and Tchws. The meter has inputs connected to sensors in a vapor compression system which provide the data for the input power and the heat absorbed parameters. One input is connected to a wattmeter set in the compressor motor power supply circuit which provides the input power.