The meter consists of two sections made of thermosetting material which move side by side, thus enabling the gas to pass through the two measuring chambers; inside such chambers, two diaphragms in rubber-coated polyester (NBR) shift causing the connecting rod/ crank assembly to move. The rotations of this assembly are counted by the index.

The two half-chambers of such device, which causes an extremely flat error curve through the whole flow rate range and a particularly low pressure absorption, are perfectly and separately calibrated through valve stroke and advanced opening setting. The use of selected materials and the optimized design ensures constant performances throughout the meter life. Both production cycle and incoming material undergo a strict quality control. The calibration is carried out at internal Metrological Laboratory by highly qualified technicians and by means of sophisticated electronic test benches.