Absolute pressure and differential pressure transmitters are used at gas custody transfer sites. Custody transfer can be between provinces/states, countries or suppliers and buyers.
Accurate pressure readings are needed so that gas used/transferred can be properly recorded and charges for the transfer can be assessed. The greater the accuracy in the pressure measurement, the better the confidence in the price of the gas transferred. Buyers can be confident they are getting what they pay for, and sellers can be confident they are fairly compensated for the product they are selling
The measurement for a typical orifice plate flow meter consists of a line pressure and a differential pressure. To calibrate both of these at the highest accuracy, a calibrator with two differently ranged sensors is needed, one for the line pressure and one for the differential pressure.
The Mensor CPG2300 has two sensors with accuracy of 0.015%FS - one can be ranged high enough to calibrate the line pressure and the other low enough to calibrate the differential pressure of each transmitter. The highest accuracy for flow can be achieved with one instrument in the CPG2300.