Deadweight Tester / Pressure Balances

LR-Cal deadweight tester / pressure balances are compact and powerful primary standars with excellent running characteristics, based on the physical principle of Pressure = Force / Area.

The direct measurement of the pressure (p = F/A), as well as the use of high-quality materials enable this small measurement uncertainty, in conjunction with an excellent long-term stability (recommended cycle of 5 years in accordance with the German Calibration Service DKD/DAkkS).

Through the selection of a dual-range piston-cylinder system (hydraulic model LR-Cal LDW-H only) with automatic measuring range switching, this measurement uncertainty can be ensured, even with a single measuring system, over a large pressure range.

Operating principle

Mass pieces placed on the top of a piston-cylinder system are the source of a precisely defined force. By producing a certain pressure (counter pressure) inside the deadweight tester / pressure balance by using e.g. the integrated hand pump, an equilibrium is achieved. In the state of equilibrium the pressure is high enouph, that the mass pieces, incl. the free-running piston of the piston-cylinder system, are floating, which will lead to a very accurate pressure at the test port.

The resource needed in this case is a pressure supply, but only for pneumatic applications >10 bar or a vacuum source for negative pressure versions.

Benefit: Large measuring range coverage is possible, long recalibration intervals and stand-alone operation

Key features:

  • Primary standard for pressure
  • Rigid basements with integrated manual pressure source
  • Excellent repeatability
  • Uncertainties mathematical calculable
  • Mechanical/physical basic principle
  • Pneumatic models (with ambient air or nitrogen)
  • Hydraulic models (up to 5,000 bar)
  • Differential pressure model with real static pressure



Hydraulic, compact design
Ranges from 1...120 bar to 10...1,200 bar and from 10...1,600 psi to 100...16,000 psi
Accuracy:  ±0.025% of measured value or ±0.05% of measured value


Hydraulic, several operating fluids
Ranges from 1...120 bar to 1...1,400 bar and from 10...1,600 psi to 10...20,000 psi
Accuracy ±0.006% of measured value or ±0.015% of measured value


Pneumatic also with Vacuum option
Ranges from 0.03...2 bar to 0.4...100 bar and 0.435...30 psi to 5.8...1.500 psi
Vacuum -0.03...-1 bar / -0.435...-14 psi
Accuracy ±0.008% of measured value or ±0.015% of measured value

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Hydraulic, high pressure
Ranges from 25...2,500 bar to 25...5,000 bar and from 350...40,000 psi to 350...70,000 psi
Accuracy ±0.020% of measured value or ±0.025% of measured value

LR-Cal CPB5600-DP


Differential presure with real static pressure
Ranges (= static pressure + differential pressure):
Pneumatic: 2 bar to 100 bar / 30 psi to 1,500 psi
Hydraulic: 60 bar to 1,000 bar / 1,000 psi to 14,500 psi
Accuracy ±0.008% of measured value or ±0.015% of measured value

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