Deadweight Tester / Differential Pressure Balance
Model LR-Cal CPB5600-DP
Differential pressure at real static pressure
Differential Pressure Deadweight Tester (Pressure Balance) for a real calibration of differential pressure under static pressure.
Accuracy (uncertainty) up to ±0.008% or ±0.015% of measured value (plus 0.0001% of the static pressure)
Applications:
- Reference instrument for the calibration of differential pressure measuring instruments under static pressure
- Primary pressure standard for calibration laboratories and factory, for the testing, adjustment and calibration of differential pressure instruments
- Complete stand-alone system, also suitable for on-site use
Features:
- Measuring range (= static pressure + differential pressure) up to 400 bar pneumatic and up to 1,000 bar hydraulic
- Total measurement uncertainty to 0.008% of differential pressure plus 1 ppm of static pressure
- Including factory calibration certificate; DAkkS certificate as option
- High long-term stability with recommended recalibration cycle every 5 years
- Masses made from stainless steel and aluminium, can be manufactured to local gravity
Description
LR-Cal CPB5600-DP Description
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 CPB5600-DP 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 CPB5600-DP 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 pressure setting depends on the instrument design and is either done via an integrated pump or from external pressure supply via a metering valve. For fine adjustment, a very precisely controllable spindle pump is fitted, with a precisions 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.
The LR-Cal CPB5600-DP instrument bases are available in the following four designs:
- Pneumatic base
- up to max. 100 bar / 1,500 psi
- with integraded pressure generation (priming pump + spindle pump)
- connection for external pressure supply
- Pneumatic base with integrated gas to oil separator
- up to max. 400 bar / 5,000 psi
- connection for external pressure supply
- for use with hydraulic piston-cylinder-systems with M30x2 connection
- test items can be easily, dryly and cleanly calibrated with air
- Hydraulic base
- up to max. 1,000 bar / 14,500 psi
- with integraded pressure generation (priming pump + spindle pump)
(on request special version available to 1,600 bar / 23,200 psi)
The instruments include the components of two pressure balances in one housing. For the calibration of differential pressure gauges under a static pressure, the two systems are separated by a by-pass valve.
One of the systems is used to generate the static pressure, with the second system generating the differential pressure (incl. static pressure). It is recommended that one of the sets of trim-masses is used for this (see accessories).
The instrument bases, pneumatic to 100 bar and hydraulic to 1,000 bar are fitted with quick-release meachnism. This enables a quick and safe replacement of the piston-cylinder systems without any tools. The pneumatic instrument design with separator is fitted with a connection for the piston-cylinder systems with M30 x 2 female thread and the hydraulic high-pressure base version is fitted with a M30x2 female thread with sealing cone.
Piston-cylinder-system
LR-Cal CPB5600-DP Piston-cylinder-system
Both, the piston and cylinder are manufactured from tungsten carbide. Compared to other materials, tungsten carbide has very small pressure and thermal expansion coefficients, which results in a very good linearity of the effective cross-sectional area of the piston and thus a high measurement accuracy.
Piston and cylinder are very well protected against contact, impacts or contamination from outside in a solid stainless-steel housing. At the same time, overpresser protection is integrated, which prevents the piston from beeing forced out vertically and avoids damage to the piston-cylinder system in the event of mass removal under pressure.
The masses are stacked on an overhang (bell jar), which sits on the piston shaft. The construction of the overhang (ball jar) provides a very low centre of gravity for the stacked weights, which minimises both the side thrust on the piston-cylinder system and the friction. For relatively low starting pressure, a lighter aluminium plate can be used instead of the overhang (bell jar).
The overall design of the piston-cylinder unit and the very precise manufacturing of both the piston and the cylinder, ensure excellent operating characteristics with a long free-rotation time, low sink rates and a very high long-term stability. Therefore, the recommended recalibration interval is 5 years.
Set of masses
LR-Cal CPB5600-DP Set of masses
In the datasheet (see DOWNLOADs) you find the tables of weights, showing the number of masses within a set of masses with their nominal mass values and the resulting nominal pressures for the respective measuring ranges. Should you not operate the device under reference conditions (ambient temperature 20°C, air pressure 1,013 mbar, relative humidity 40%), relevant corrections must be made.
The masses are calibrated, as standard, to the standard gravity (9.80665 m/s²), although they can be manufactured for any particular location.
Specification
LR-Cal CPB5600-DP Specification
| PNEUMATIC Range 1) 2) 6) |
bar | 0.03...2 | 0.2...10 | 0.4...50 | 0.4...100 | ||
| Required masses | kg | 10 | 10 | 10 | 20 | ||
| Smallest Step 3) | bar | 0.01 | 0.05 | 0.25 | 0.25 | ||
| Sensitivity 4) | mbar | 0.002 | 0.01 | 0.05 | 0.05 | ||
| Nominal cross-sectional area of the piston | mm² | 5 | 1 | 0.2 | 0.2 | ||
| PNEUMATISC Range 1) 2) 6) |
psi | 0.435...30 | 2.9...150 | 5.8...500 | 5.8...1,000 | 5.8...1,500 | |
| Required masses | kg | 10 | 10 | 7 | 13 | 20 | |
| Smallest step 3) | psi | 0.2 | 1 | 5 | 5 | 5 | |
| Sensitivity 4) | psi | 0.00003 | 0.00015 | 0.00075 | 0.00075 | 0.00075 | |
| Nominal cross-sectional area of the piston | cm² | 5 | 1 | 0.2 | 0.2 | 0.2 | |
| HYDRAULIC Range 1) 2) 6) |
bar | 0.2...60 | 0.2...100 | 1...250 | 1...400 | 2...600 | 2...1,000 |
| Required masses | kg | 30 | 50 | 25 | 40 | 30 | 50 |
| Smallest step 3) | bar | 0.1 | 0.1 | 0.5 | 0.5 | 1 | 1 |
| Sensitivity 4) | mbar | 0.04 | 0.04 | 0.2 | 0.2 | 0.4 | 0.4 |
| Nominal cross-sectional area of the piston | cm² | 0.5 | 0.5 | 0.1 | 0.1 | 0.05 | 0.05 |
| HYDRAULIC Range 1) 2) 6) |
psi | 2.9...1,000 | 14.5...5,000 | 29...10,000 | 29...14,500 | ||
| Required masses | kg | 34 | 34 | 34 | 50 | ||
| Smallest step 3) | psi | 2 | 10 | 20 | 20 | ||
| Sensitivity 4) | psi | 0.006 | 0.003 | 0.006 | 0.006 | ||
| Effective area | cm² | 0.5 | 0.1 | 0.05 | 0.05 | ||
| Accuracy 7) | % of measured value |
proportion of static pressure: 0.0001 proportion of differential pressure: 0.015 / optional: 0.008 (high-pressure hydraulic version: 0.025 / optional: 0.020) |
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| Lower limiting value of measurement uncertainty | depends on range; corresponds to sensitivity of piston | ||||||
| Basement versions | |||||||
| Pneumatic | up to 100 bar / 1,500 psi; with priming pump, spindle pump and port for external pressure supply | ||||||
| Pneumatic with separator | up to 400 bar / 5,000 psi; for external pressure supply, with integrared separator air on oil | ||||||
| Hydraulic | up to 1,000 bar / 14,500 psi; with internal pressure supply (on request version up to 1,600 bar / 23,200 psi available) |
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| Pressure ports | |||||||
| Piston-cylinder-unit | Quick-fit connection for basement versions pneumatic and hydraulic; M30 x 2 male thread for basement version pneumatic with separator |
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| Test item | 2 pcs. quick-fit connections 1/2" BSP female rotating, other threads see accessories | ||||||
| Pressure medium | |||||||
| Pneumatic | clean and dry non-corrosive gases (e.g. air or nitrogen) | ||||||
| Hydraulic | special oil (1 l included in supply) | ||||||
| Oil reservoir | cm² | 250 | |||||
| External pressure supply | 6 mm SWAGELOK (R) tube fitting; max. 110% of used pressure range (only for basement version pneumatic or version pneumatic with separator) | ||||||
| Materials | |||||||
| Piston | Tungsten Carbid | ||||||
| Cylinder | Tungsten Carbid | ||||||
| Set of masses | Stainless steel 1.4305 and aluminium, non-magnetic | ||||||
| Tubes / pipes in basement | |||||||
| Pneumatic | Stainless steel 1.4571, 3 x 1 mm | ||||||
| Hydraulic | Stainless steel 1.4404, 6 x 2 mm | ||||||
| Operating conditions | |||||||
| Operating temperature | °C | 18...28 | |||||
| Weight | |||||||
| Basement pneumatic | kg | 34.0 | |||||
| Basement pneumatic with separator | kg | 32.0 | |||||
| Basement hydraulic | kg | 38.5 | |||||
| Piston-cylinder-unit | kg | 1.5 (5.7 incl. bell jar and base weight, in optional carrying case (2 units required) | |||||
| BAR weight set, pneumatic | kg | 32.4 (incl. 2 wooden cases) | |||||
| BAR extension weight set, pneumatic | kg | 28.0 (incl. 2 wooden cases) | |||||
| BAR weight set, hydraulic | kg | 72.0 (incl. 2 wooden cases) | |||||
| BAR extension weight set, hydraulic | kg | 48.0 (incl. 2 wooden cases) | |||||
| PSI weight set, pneumatic | kg | 25.0 (incl. 2 wooden cases) | |||||
| PSI extension weight set 1, pneumatic | kg | 22.0 (incl. 2 wooden cases) | |||||
| PSI extension weight set 2, pneumatic | kg | 37,0 (incl. 2 wooden cases) only for range 1,500 psi | |||||
| PSI weight set, hydraulic | kg | 84,0 (incl. 2 wooden cases) | |||||
| PSI extension weight set, hydraulic | kg | 43,0 (incl. 2 wooden cases) | |||||
| Dimensions | |||||||
| Basement | mm | W 800 x D 375 x H 265 | |||||
| Wooden case for weight set | mm | W 400 x D 310 x H 310 | |||||
| Wooden case for extension weight set | mm | W 215 x D 310 x H 310 | |||||
| Optional case for piston-cylinder-unit | mm | W 300 x D 265 x H 205 | |||||
| Certificates | |||||||
| CE-Conformity | 97/23 EG (module A), only for versions above 1,000 bar | ||||||
| Calibration | Factory Certificate of Calibration (optional: DKD-/DAkkS-Certification), traceable | ||||||
1) Measuring range = static pressure + differential pressure.
2) 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.
3) 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).
4) The sensitivity is the threshold of the measuring system. It is the pressure value of the smallest mass-addition, which brings the piston-cylinder system clearly and reproducibly out of balance.
5) Measurement uncertainty assuming reference conditions (ambient temperature 20°C, air pressure 1,013 mbar, relative humidity 40%). Corrections must be calculated, if required.
6) Other on request.
7) The accuracy of the differential pressure is determined in accordance with the calculation basis shown in the datasheet (see DOWNLOADs).
LR-Cal CPB5600-DP Scope of delivery + Options
Scope of supply:
- Base
- Priming pump
- Spindle pump (2 x) for pressure generation / fine adjustment
- Piston adapter (2 x): quick-release for pneumatic and hydraulic base; M30x2 female thread for pneumatic base with separator and high-pressure hydraulic base
- Quick-connectors (2 x) for test item
- Piston-cylinder-systems with overhangs (bell jars) (2 x)
- Basic mass sets in carrying cases (2 x)
- Extension mass sets in carrying case, depending on the measuring range (2 x)
- Mass sets manufactured to standard gravity 9.80665 m/s²
- Operating fluid (for hydraulic versions or pneumatic version with separator)
- Manual in English and German language
- Factory Certificate of Calibration, traceable
Options:
- Systems with increased accuracy to 0.008% (depending on measuring range)
- Storage case for piston-cylinder systems
- Mass set manufactured to local gravity
- DAkkS-certification
Accessories
LR-Cal CPB5600-DP Accessories
| Order-Code | Description | Image |
| LDW-FMS-F1 | Set of trim-masses, Class F1 (1 x 50 g, 2 x 20 g, 1 x 10 g, 1 x 5 g, 2 x 2 g, 1 x 1 g, 1 x 500 mg, 2 x 200 mg, 1 x 100 mg, 1 x 50 mg, 2 x 20 mg, 1 x 10 mg, 1 x 5 mg, 2 x 2 mg, 1 x 1 mg |
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| LDW-FMS-M1 | Set of trim-masses, Class M1 (1 x 50 g, 2 x 20 g, 1 x 10 g, 1 x 5 g, 2 x 2 g, 1 x 1 g, 1 x 500 mg, 2 x 200 mg, 1 x 100 mg, 1 x 50 mg, 2 x 20 mg, 1 x 10 mg, 1 x 5 mg, 2 x 2 mg, 1 x 1 mg |
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| CPB5000-ADS | As a standard, the deadweight tester is equipped with a quick-release connector 1/2" BSP female for connecting the test item. For this purpose, various threaded adapters, which can be easily changed, are available: Set of adapters: 1/4" BSP, 3/8" BSP, 1/2" NPT, 1/4" NPT and M20x1.5 female |
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| CPB5000-ADS-NPT | Ditto, set of NPT adapters: 1/8" NPT, 1/4" NPT, 3/8" NPT, 1/2" NPT female | |
| CPB5000-WA90 | 90° angled adapter for test items with pressure connection at the back side |  |
| CPB5000-TV-1000 | Separator (without diaphragm), Pmax 1000 bar | |
| CPB5000-R-SET | Set of O-Rings (for piston and test items): 5 pcs. each 8 x 2 and 4 x 2.2 |  |
| CPB5000-PN-RS | Cleaning set for pneumatic piston-cylinder-systems CPB5600-DP | |
| CPB5000-HY-RS | Cleaning set for hydraulic piston-cylinder-systems CPB5600-DP |
DOWNLOADs
LR-Cal CPB5600-DP Datasheet / Operating manual
Excel Sheet
MS Excel sheet to calculate corrections (air density, piston temperature, local gravity) and masses/pressure calculations.
