Rotary gas meters are designed to meet the highest demands for reliable and accurate measurement of gas flow. The meters are MID approved and fully comply with OIML R137 standards. The compact, replaceable aluminum cartridge allows for local repair and on-site cleaning. The robust design of the housing and cartridge makes the meter less susceptible to installation stresses caused by connection pipes.

The aluminum body of the meter (body and front plate) is designed with a safety factor of 4 for operating pressures up to 20 bar. Square vanes and improved positioning of the main bearings and shafts make the meter less susceptible to overload and pressure surges. The protection of the aluminum index and LF pulsars with associated magnets makes the meters less susceptible to manipulation by externally applied magnets or other external forces.

The unique lubrication system, where oil is distributed directly to the timing gears through a disc, eliminates oil loss at high rotor speeds and lubricates the timing gears at very low loads. All plugs and oil level indicators are at the front of the meter, allowing the meter to be installed in very compact installations.

The rotary gas meter operates on the positive displacement principle. The actual measurement is performed by two figure-eight-shaped vanes (rotors) rotating in the measurement chamber. During a full rotation of the rotors, a fixed volume is displaced from the meter inlet to the outlet. The number of rotations represents the passed volume. The volume is directly indicated on the meter index. Various low and high-frequency pulsars can be used for flow calculation or control purposes.

The FMR series rotary meters are suitable for legal measurement of all non-corrosive gases such as natural gas, propane, butane, air, hydrogen.