The Fluke 721 Precision Pressure Calibrator has special features that support the complete calibration of natural gas multi-variable electronic flowmeters and other types of flow computers. With two internal pressure ranges, external Fluke 750P pressure modules and an optional precision RTD probe, all of the calibrations required for the flow computer can be performed with just one instrument. The Fluke 721 is available with two built-in pressure ranges from from 16 psi/1 bar up to 5000 psi/345 bar. For this application, the configuration with the low pressure sensor (P1) 16 psi/1 bar and high pressure sensor (P2) of 1500 psi/100 bar is frequently the best fit. Since the Fluke 721 has an accuracy specification as a percent of full scale, it is important to closely match the full scale of the calibrator to the scale of the application in order to get the best performance.
In addition to the calibrator itself, a high and low pressure calibration pressure source will be needed. An accessory RTD probe is also required for measuring temperature. An appropriate low pressure source with 0.01 in H2O of resolution is needed for the low pressure test, and a high pressure source such as a regulated nitrogen bottle or hydraulic hand pump are required. One pump style typically does not work well for both tests or extensive cleaning is required to switch from hydraulic (oil or water) to pneumatic testing. High pressure pumps typically do not have the desired resolution for the low pressure test.
Download the Fluke Oil and Gas Brochure