These types of metres are commonly used in Oxygen tanks and are usually comprised of a pressure gauge and a variable area meter, more commonly known as a Rotameter. The rotameter is very common in hospitals and laboratory applications as an air flow meter device. The rotameter is not limited to certain types of gas but can be pre fabricated for use as a nitrogen flow meter or as a specialty gases .

The regulator is coupled to the oxygen flow meter and by visual inspection the user is able to see the flow rate by a flow scale marked on the rotameter. Combining the rotameter and oxygen regulator as a complete set creates a new product called an oxygen flow controller.

Mass Air Flow Meters

Other industries also require air or gas flow controllers. Not only for oxygen flow applications but also for natural gas, compressed air, hydrogen monitoring, land fill gas monitoring and chlorine gas.

The control processes can be of multiple types and are normally automated and so it is important to use a device that is relatively accurate, reliable, easy to install and affordable. This is where the Mass Flow Meter comes into play. This is an air consumption meter that measures how much air is flowing through a tube. IT does not measure the volume of the air passing through the tube but the actual speed of the air flowing through the device in a defined time segment. Typically, mass air flow measurement is expressed in the units of kilograms per hour.