Pressure calibration is the comparison of the output of a device used to measure pressure with that of another pressure measurement device, or pressure measurement standard. This usually involves plumbing the device under test (DUT) to the standard device and generating a common pressure in the measurement circuit. The outputs of the devices are compared at one or more pressures, typically from the lowest to highest readings of the DUT’s full-scale range, or the range for which it is normally used. This comparison process is performed in a chain from the highest level of fundamental pressure realization, down to everyday pressure measurement devices, to ensure pressure measurements are accurate and comply with accepted or mandated standards.
A National Metrology Institute (NMI) is an institution responsible for realizing and disseminating measured values according to the International System of Units (SI). There is typically one NMI in each country, formally designated, and in some countries mandated to enforce metrology standards in industry and science. Fluke Calibration piston gauges are widely used in NMI laboratories worldwide to fundamentally determine and disseminate pressure values with low uncertainties. Fluke Calibration offers PG9000 piston gauges, specifically designed for metrology institutes to realize and disseminate pressure values with direct traceability to dimensional measurements.
Primary calibration laboratories provide a link from national metrology institutes or fundamentally derived measurements to secondary laboratories and working standards. These laboratories typically perform very high precision calibrations in low volumes and include top military, research, corporate, and commercial calibration labs. A primary pressure calibration laboratory typically utilizes fundamental pressure standards, such as PG7000 or 2400 piston gauges, with traceability through a national metrology institute or another primary calibration laboratory. To disseminate primary pressure values to working standards, these labs may also use high-performance transfer standards, such as PPC/RPM and 7000 pressure controller/calibrators and reference pressure monitors or Pressurements deadweight testers.
A majority of the facilities in the world that perform pressure calibrations utilize transfer or working standards to support pressure measurement devices (pressure gauges, transmitters, transducers, etc.) and other working calibration standards. These laboratories can perform a range from basic tests to high precision calibrations, and typically in higher volumes than an NMI or primary calibration laboratory. The traceability of pressure standards is maintained through a primary laboratory or another secondary calibration lab. To support working standards and high-performance measurement devices, a secondary pressure lab typically utilizes high-performance transfer standards, such as PPC/RPM and 7000 pressure controller/calibrators and reference pressure monitors or Pressurements deadweight testers. PG7000 or 2400 piston gauges can be used for more demanding applications. Everyday calibration of measurement devices and lower performance working standards can use the same high-performance transfer standards or working standards such as E-DWT electronic deadweight tester or PPC4E pressure controller/calibrator.