Thermal Mass Flow Meter is an option provided by Process Control Devices for monitoring compressed air and gas usage. The thermal mass system is capable of measuring gas mass flow. This technology may provide a lot of insight into how your industry uses their resources through pipelines. Also, thermal mass flow metering is appropriate for other gases that may be compatible such as nit... https://www.pcd-flowmeter.com/flow-meter/thermal-mass-flow-meter-manufacturer