pressure calibrator / digital / precision / laboratory
FRS4 Furness Controls



  • Measured physical value:


  • Options:

    digital, precision, laboratory, low-pressure

  • Pressure:

    Min.: 0 Pa (0 psi)

    Max.: 44,000 Pa (6.38 psi)


Key Features
- A unique primary standard for low-pressure scenarios
- Pressure calibration range from 0.001 Pa to 44k Pa
- Typical uncertainty of ± 0.005 % reading + 0.02 Pa
- Used worldwide in national & accredited laboratories
- New 2017 version now available

Used in laboratories throughout the world, the Furness Controls Reference Standard (FRS4) is a high-resolution low-pressure standard directly traceable to national standards via mass and linear measurement. The instrument is the gold standard for the calibration of both gauge pressure and differential pressure. Its unique design allows high levels of accuracy at very low pressure levels, in the range where competing instruments begin to experience uncertainty.

Producing a standardised pressure requires precise knowledge of the metrics of the physical components involved. The FRS4 uses regulated air flow over a piston with precisely known mass and dimensions, a high accuracy digital balance, and a precision control unit. With these components the FRS4 is able to generate a precise differential pressure for use in the calibration of a multitude of devices, such as capacitance diaphragm gauges, and low-pressure transmitters and transducers.

Precise Construction
The piston is suspended centrally in a cylinder using a parallelogram suspension system, and both are precision-engineered from Invar, a nickel-iron alloy with a low thermal expansion coefficient. This gives an area expansion coefficient at room temperature of around 4 ppm.

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