Abstract: An apparatus and method for controlling and metering gas flowing through a pipeline is provided. The apparatus includes an orifice flow meter for accurately measuring the flow rate of gas through the pipeline within a certain range. The apparatus further includes a turbine flow meter which provides a measurement of the flow rate of the gas flowing through the pipeline over a broad range. A control circuit coupled to the turbine flow meter is provided for evaluating the flow rate to determine whether the flow rate is higher than a predetermined maximum value which can be recorded by the orifice flow meter or lower than a predetermined minimum value which can be recorded by the orifice flow meter. If the flow rate is higher than the predetermined maximum value, the control circuit generates a first voltage signal, if the flow rate is lower than the predetermined minimum value, the control circuit generates a second voltage signal.

Abstract: A temperature and pressure compensated gas flowmeter is provided which reads uncompensated line parameters and outputs a frequency signal representative of the gas flow rate referenced to standard conditions. The frequency signal is compatible with a number of interface devices, such as remote terminal units, field computers and displays. Further, the uncompensated line parameters are also provided to the interface devices such that the compensated frequency signal can be verified.