Deadweight Tester (Pressure Balance, Primary Pressure Standard),
hydraulic, Ranges from 25...2,500 bar to 25...5,000 bar and 350...40,000 psi to 350...70,000 psi
or with dual piston system with range 1...2,600 bar / 10...40,000 psi.
Accuracy (measurement uncertainty) ±0.020% or ±0.025% of measured value.
Applications:
Features:
Proven primary pressure standard
Deadweight Tester / Pressure Balances are the most accurate instrument available on the market for the calibration of electronic or mechanical pressure measuring instruments. The direct measurement of the pressure (p = F / A), as well as the use of high-quality materials enable a very small measurement uncertainty, in conjunction with an excellent long-term stability of 5 years (recommended in accordance with German Calibration Service DKD/DAkkS).
The deadweight tester / pressure balance has therefore been used for years in factory and calibration laboratories in national institutes, research laboratories and in industry.
Stand-alone operation
Due to its integrated pressure generation and the pure mechanical measuring principle, the model LR-Cal CPB5000-HP is ideal for on-site use for maintenance and service.
Basic principle
Pressure is defined as the quotient of force and area. The core component of the model LR-Cal CPB5000-HP is therefore a very pecisely manufatured piston-cylinder-system, which is loaded with masses in order to generate the individual test points.
The masses applied are proportional to the target pressure and this is achieved through optimally graduated weights. As standard, these masses are manufactured to the standard gravity (9.80665 m/s²), though the can be manufactured to a specific location (gravity) and also DAkkS-calibrated.
Easy operation
The setting of the pressure is made via an integrated pump. For fine adjustment, a very precisely controllable spindle pump is fitted, with a spindle running within it.
As soon as the measuring system reaches equilibrium, there is a balance of forces between the pressure and the mass load applied. The excellent quality of the system ensures that this pressure remains stable over several minutes, so that the pressure value for comparative measurements can be read without any problems, or also so that more complex adjustments can be carried out on the test item.
Robust instrument design
With the high-pressure model LR-Cal CPB5000-HP, calibrations up to a maximum pressure of 5,000 bar are possible.
It is built into a stable base and offers exceptional ease-of-use. With the integrated priming pump and the 250 ml tank, large test volumes can also be easily filled and primed.
The piston-cylinder systems are availablein two fundamentally different designs, depending on measuring range:
High accuracy over a wide measuring range
The dual-range piston-cylinder system (version with range 2,600 bar only) offers two measuring ranges in one housing with automatic measuring range switching from low-pressure to high-pressure pistons. This provides the user with an extremely flexible measuring instrument that can cover a wide measuring range with high accuracy, with only one piston-cylinder unit and one set of weights. Additionally two test points can automatically be achieved by the operator loading masses once.
The piston and cylinder are manufactured from hardened steel and tungsten carbide, respectively. This pairing of materials has very low pressure and temperature coefficients of expansion, which results in a very good linearity for the cross-sectional area and a very high accuracy.
The overall design of the piston-cylinder unit and the very precise manufacturing of both the piston and the cylinder, ensure exceptionally low friction force, which results in excellent operating characteristics with long free-rotation time and low sink rates. Thus a high long-term stability is ensured. Therefore the recommended recalibration interval is five years depending on the conditions of usage.
Both test connections are fitted with knurled nuts and exchangeable thread adapters with sealing cones. M16 x 1.5, M20 x 1.5 and 9/16-18 UNF thread adapters with male threads are included in the scope of delivery.
The table in the datasheet (see DOWNLOADs) show, for the respective measuring range, the number of masses within a set of masses, with their resulting nominal pressures.
Should you not operate the instrument under reference conditions (ambient temperature 20°C, air pressure 1,013 mbar, relative humidity 40%), the relevant corrections must be made.
Design | Single-piston | Dual-piston | |||
Measuring range 1) | bar | 25...2,500 | 25...4,000 | 25...5,000 | 1...50/20...2,600 |
Required masses | kg | 50 | 80 | 100 | 107 |
Smallest step (standard mass set) 2) | bar | 2,5 | 2,5 | 2,5 | 0.5/10 |
Nominal cross-sectional area of the piston | cm² | 0.02 | 0.02 | 0.02 | 0.8065/0.0403 |
Measuring range 1) | psi | 350...40,000 | 350...60,000 | 350...70,000 | 10...600/200...40,000 |
Required masses | kg | 55 | 83 | 97 | 119 |
Smallest step (standard mass set) 2) | psi | 50 | 50 | 50 | 5/100 |
Nominal cross-sectional area of the piston | cm² | 0.02 | 0.02 | 0.02 | 0.8065/0.0403 |
Accuracy 3) 4) | % of measured value |
0.025 / optional 0.02 | 0.025 / optional 0.007 | ||
Pressure transmission medium | up to 4,000 bar / 60,000 psi: hydraulic fluid based on VG22 mineral oil (1 litre included in scope of delivery) 5,000 bar / 70,000 psi: Sebacate oil (0.5 litre included in scope of delivery) |
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Fluid reservoir | cm² | 250 | |||
Test item connection | rotatable, including three male adapters M16 x 1.5 / M20 x 1.5 and 9/16-18 UNF |
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Material | |||||
Piston | hardened steel | Tungsten carbide / steel | |||
Cylinder | Tungsten carbide | Steel / tungsten carbide | |||
Set of masses | Stainless steel 1.4305, non-magnetic | ||||
Piping in instrument base | Stainless steel 1.4404, 6 x 2 mm | ||||
Permissible ambient conditions |
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Operating temperature | °C | 18...28 | |||
Weights | |||||
High pressure basement | kg | 32.5 | |||
Piston-cylinder system | kg | 2.7 (5.0 incl. storage case) | |||
BAR basic set of masses, case 1 | kg | 34.0 | 34.0 | 34.0 | 43.3 |
BAR basic set of masses, case 2 | kg | 27.5 | 27.5 | 27.5 | 29.7 |
BAR basic set of masses, case 3 | kg | --- | --- | --- | 29.4 |
BAR basic set of masses, case 4 | kg | --- | --- | --- | 29.4 |
BAR extension set of masses, case 1 | kg | --- | 33.5 | 33.5 | --- |
BAR extension set of masses, case 2 | kg | --- | --- | 23.5 | --- |
PSI basic set of masses, case 1 | kg | 51.0 | 51.0 | 51.0 | 40.5 |
PSI basic set of masses, case 2 | kg | 15.0 | 15.0 | 15.0 | 33.6 |
PSI basic set of masses, case 3 | kg | --- | --- | --- | 33.6 |
PSI basic set of masses, case 4 | kg | --- | --- | --- | 31.6 |
PSI extension set of masses, case 1 | kg | --- | 31.8 | 31.8 | --- |
PSI extension set of masses, case 2 | kg | --- | --- | 17.8 | --- |
Dimensions | |||||
Base | mm | W 460 x D 445 x H 265 | |||
Carrying case 1 for basic set of masses | mm | W 400 x D 310 x H 310 | |||
Carrying case 2-4 for basic set of masses | mm | W 215 x D 310 x H 310 | |||
Carrying case for extension set of masses | mm | W 215 x D 310 x H 310 | |||
Storage case for piston-cylinder system | mm | W 370 x D 150 x H 150 | |||
Approvals and certificates |
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CE conformity | Pressure equipment directive 97/23/EC (module A) | ||||
Calibration | Traceable factory certificate of calibration Optional: DAkkS-Certificate for single-piston versions or UKAS for dual-piston version |
1) Theoretical starting value; corresponds to the pressure value generated by the piston (by its own weight). To optimise the operating characteristics, more weights should be loaded.
2) The smallest pressure change value that can be achieved based on the standard weight set. To reduce this, a set of trim-masses is available (see accessories).
3) The accuracy from 10% of the measuring range is based on the measured value. In the lower range, a fixed error based on 10% of the range applies.
4) Measurement uncertainty assuming reference conditions (ambient temperature 20°C, air pressure 1,013 mbar, relative humidity 40%). Corrections must be made if required.
Scope of standard delivery:
Options:
MS Excel sheet to calculate corrections (air density, piston temperature, local gravity) and masses/pressure calculations.