Dergi makalesi Açık Erişim

Metrological characterisation of force-balanced piston gauge up to 15,000 Pa pressure range

2023    Durgut, Y.

Pressure balance is a pressure standard used to measure pneumatic or hydraulic pressure. It operates using the produced force value over a calibrated area. The force is applied to a piston-cylinder assembly, with the gravitational force of the calibrated loaded weights realised by a piston-cylinder (PC) assembly. Such instruments are also called piston gauges (PGs) and are used as primary-level standard instruments in pressure metrology. The current pressure ranges for conventionally available piston gauges start from a few kilopascals, which is the lowest achievable pressure limit value for a piston gauge. Owing to the pressure limitations, it is not possible to use piston gauges for certain small pressure ranges. To overcome such limitations, Fluke launched an instrument which is a non-rotating force-balanced piston gauge FPG model 8601 from 1 to 15 000 Pa. The TUBITAK UME National Metrology Institute of Turkey bought and performed a metrological characterisation of his FPG8601 standard up to 15 kPa pressure range. First, the effective area of the piston-cylinder unit (PCU) of FPG8601 was determined using the cross-float method offered by the manufacturer, against the reference piston pressure balance of the model PG7601. The obtained effective area calibration results were compared with those of previous calibration certificates by Fluke and Minerva. All results were within the 7-ppm agreement interval. Second, the effective area value obtained from the calibration was entered into the FPG software and the pressure values indicated by the FPG8601 standard were checked against the reference pressure values applied from the reference piston gauge. The deviations and assigned uncertainties were evaluated. It was concluded that the results after characterisation were within the tolerance values declared by the manufacturer.