Krohne has updated the Optisonic 7300 Biogas ultrasonic flow meter for the measurement of dry and wet (raw) biogas with variable composition. Besides the standard temperature sensor, it now features a pressure sensor that can be ordered optionally with the flow meter and comes mounted on the flow tube.
In combination with the integrated flow computer, the additional sensor provides for advanced biogas measurement, since the methane content of biogas may vary it may be required for the operation of the biogas facility to know the exact content in a methane/CO2 mixture, e.g. when the gas is used as fuel for engines in a CHP unit. Here, a temperature sensor in combination with the measured velocity of sound enables direct measurement of methane content via calculation of the molar mass.