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.

压力平衡是用于测量气压或液压的压力标准。它使用在校准区域上产生的力值进行操作。该力施加到活塞-气缸组件上，校准负载重物的重力由活塞-气缸 (PC) 组件实现。此类仪器也称为活塞式压力计 (PG)，在压力计量学中用作初级标准仪器。传统可用活塞式压力计的当前压力范围从几千帕开始，这是活塞式压力计可实现的最低压力限值。由于压力限制，不能将活塞式压力表用于某些小压力范围。为了克服这些限制，Fluke 推出了一款非旋转力平衡活塞式压力计 FPG 型号 8601，压力范围为 1 至 15 000 Pa。土耳其 TUBITAK UME 国家计量研究所购买并对其 FPG8601 标准高达 15 kPa 的压力范围进行了计量表征。首先，根据 PG7601 型号的参考活塞压力平衡，使用制造商提供的交叉浮动法确定 FPG8601 活塞缸单元 (PCU) 的有效面积。将获得的有效面积校准结果与 Fluke 和 Minerva 之前的校准证书进行了比较。所有结果均在 7 ppm 一致区间内。第二，将从校准中获得的有效面积值输入到 FPG 软件中，并将 FPG8601 标准指示的压力值与来自参考活塞压力表的参考压力值进行核对。对偏差和指定的不确定性进行了评估。得出的结论是，表征后的结果在制造商声明的公差值范围内。