to a coriolis a vortex a turbine a variable area an electromagnetic and an ultrasonic type flowmeter depending on the type of flowmeter that is used one or more variables of the fluid may be measured in this exemplary embodiment the flowmeter 46 measures the volumetric flowrate of the unodorized natural gas flowing through the flowmeter 46 the controller 30 as seen in fig5 may comprise a program memory 52 a microcontroller or microprocessor mp 54 a random access memory ram 56 and an input output i o circuit 58 all of which may be interconnected via an address data bus 60 it should be appreciated that although only one microprocessor 54 is shown the controller 30 may include additional microprocessors similarly the memory of the controller 30 may include multiple rams 56 and multiple program memories 52 although the i o circuit 58 is shown as a single block it should be appreciated that the i o circuit 58 may include a number of different types of i o circuits additionally and or alternatively the controller 30 may be a programmable logic controller u201c plc u201d or any other type of mechanical and or electrical device able to activate deactivate and or control the control valve 26 the first flowmeter 28 and or.