Alicat Scientific Alicat Scientific’s MB Series portable mass flow and liquid flowmeters utilize a 9-volt battery pack for metering gas flow, pressure, or water flow in the field and lab. With eight to 10 hours of battery life, the flowmeters measure pressure, temperature and volumetric flow in addition to mass flow. The portable meters can be used to verify proper operation of flowmeters and flow controllers from many manufacturers, take measurements in the field, and to test for leaks in multiple processes or systems. The lightweight meters fit into a pocket or work bag. They may also be hardwired or wall-powered, with the battery serving as a backup during power loss to maintain critical operations monitoring. Devices come pre-calibrated (NIST traceable) for Air, Hydrogen, Helium, and Argon as well as 16 other gases and 10 gas mixes. – alicatscientific.com