The europascal BH2-400B DP Dual Piston Deadweight Tester is a high-performance hydraulic pressure standard designed for precise pressure calibration over a particularly wide measuring range. Its dual-piston configuration combines a low-pressure range from 1 to 60 bar with a high-pressure range from 5 to 400 bar, allowing one deadweight tester and one weight set to cover applications from low hydraulic pressure up to 400 bar.
With an accuracy of 0.01 %, the europascal BH2-400B DP is an excellent solution for professional calibration laboratories, industrial metrology, quality assurance, pressure instrument manufacturers and research applications.
The abbreviation DP stands for Dual Piston. In contrast to a conventional single-piston deadweight tester, the BH2-400B DP uses two precision piston-cylinder systems with different effective areas. The larger low-pressure piston allows practical generation of lower pressures, while the smaller high-pressure piston enables pressures up to 400 bar without requiring an excessively large mass stack.
The system operates hydraulically with oil and is based on the fundamental physical piston gauge principle. This provides excellent long-term stability and direct traceability through calibrated masses, gravitational acceleration and precisely characterized piston areas.
europascal supports professional users with product selection, configuration, maintenance and calibration. The europascal calibration service provides professional solutions for deadweight testers, pressure balances, pressure gauges, sensors, transmitters and other pressure measuring equipment.
Your Benefits at a Glance
The europascal BH2-400B DP Dual Piston Deadweight Tester combines a broad hydraulic measuring range with high accuracy and a robust dual-piston design.
Key benefits include:
- High-performance hydraulic deadweight tester
- Dual-piston configuration
- Two precision piston-cylinder systems
- Low-pressure range from 1 to 60 bar
- High-pressure range from 5 to 400 bar
- Overall pressure coverage from 1 to 400 bar
- Accuracy of 0.01 %
- One weight set for two measuring ranges
- Hydraulic operation with oil
- Stainless steel calibration masses
- Robust design for professional laboratory use
- Different pressure units available
- Standard or customer-specific gravity configuration
- Optional motorized weight rotation
- Optional piston position visualization
- Optional automatic pressure calculation
- Optional environmental measurement functions
- Optional PC data transfer
- Optional accredited calibration certificate
- Professional calibration and service from europascal
Dual Piston Design for a Wide Measuring Range
The most important feature of the europascal BH2-400B DP is its dual-piston configuration.
The instrument provides two measuring ranges:
Low-pressure piston: 1 to 60 bar
High-pressure piston: 5 to 400 bar
The two ranges overlap between 5 and 60 bar.
This overlap provides considerable flexibility when selecting the piston-cylinder system for a particular calibration point.
The complete pressure coverage therefore extends from:
1 to 400 bar
The dual-piston concept allows these two measuring ranges to be generated using the same calibration weight set.
This provides an important practical advantage for calibration laboratories because a broad pressure range can be covered without requiring two completely separate deadweight testers.
Measuring Ranges in bar, PSI and kPa
The two pressure ranges are specified as follows:
Low-Pressure Piston
1 to 60 bar
10 to 800 psi
100 to 6,000 kPa
High-Pressure Piston
5 to 400 bar
50 to 5,000 psi
500 to 40,000 kPa
The maximum pressure is:
400 bar / 40 MPa
This wide measuring range makes the BH2-400B DP suitable for a broad selection of hydraulic pressure calibration tasks.
Accuracy of 0.01 %
The europascal BH2-400B DP Precise Dual Piston Deadweight Tester provides a specified accuracy of:
0.01 %
This makes the system suitable for demanding calibration applications involving pressure gauges, sensors, transmitters and other industrial pressure measuring instruments.
The complete measurement uncertainty of an actual calibration additionally depends on relevant influence quantities such as:
- Calibration of the masses
- Effective piston area
- Local gravitational acceleration
- Air buoyancy
- Piston-cylinder temperature
- Pressure deformation
- Hydraulic fluid density
- Hydrostatic head
- Repeatability
- Resolution of the device under test
- Environmental conditions
These quantities should be considered when establishing a measurement uncertainty budget for high-accuracy pressure calibration.
Fundamental Piston Gauge Measurement Principle
The europascal BH2-400B DP operates according to the fundamental physical principle of a piston gauge.
Pressure is generated by applying a precisely defined force to a characterized effective piston area.
The fundamental relationship is:
p = F / A
where:
p = generated pressure
F = force acting on the piston
A = effective piston area
The force generated by the calibrated masses is primarily determined by:
F = m × g
where:
m = applied mass
g = gravitational acceleration
The simplified relationship therefore becomes:
p = (m × g) / A
For precision measurements, additional corrections can be applied for local gravity, air buoyancy, piston-cylinder temperature, pressure deformation and hydrostatic head.
Because the BH2-400B DP contains two piston-cylinder assemblies, the appropriate effective area is used according to the selected pressure range.
Why Use Two Pistons?
The pressure generated by a deadweight tester depends on the ratio between applied force and effective piston area.
For low pressures, a relatively large piston area is advantageous. It allows useful pressure values to be generated with practical calibration masses.
For higher pressures, a smaller piston area is advantageous because the same mass generates a significantly higher pressure.
The BH2-400B DP combines both principles in one instrument:
Larger piston → 1 to 60 bar
Smaller piston → 5 to 400 bar
The result is an exceptionally broad measuring range with a useful overlap between both piston systems.
This is especially valuable for calibration laboratories that regularly work with devices covering very different pressure ranges.
One Weight Set for Two Measuring Ranges
An important advantage of the dual-piston concept is that:
two measuring ranges can be obtained from the same weight set.
The operator selects the appropriate piston-cylinder system according to the required pressure.
Because the two pistons have different effective areas, the same calibrated mass produces different pressures depending on which piston is used.
This allows the BH2-400B DP to cover an overall pressure range from 1 to 400 bar while keeping the mass system practical and manageable.
Ideal for Pressure Gauge Calibration
The europascal BH2-400B DP is particularly suitable for calibration of mechanical and electronic pressure measuring instruments.
Typical devices under test include:
- Precision pressure gauges
- Digital pressure gauges
- Hydraulic pressure gauges
- Reference pressure indicators
- Pressure sensors
- Pressure transmitters
- Pressure transducers
- Pressure switches
- Process pressure instruments
- Secondary pressure standards
Common nominal pressure ranges such as 6 bar, 10 bar, 16 bar, 25 bar, 40 bar, 60 bar, 100 bar, 160 bar, 250 bar and 400 bar can therefore be covered with one physical pressure standard.
Hydraulic Operation with Oil
The europascal BH2-400B DP is a hydraulic deadweight tester.
Oil is used as the pressure transmission medium.
Hydraulic operation provides stable pressure generation and is particularly suitable for industrial pressure calibration up to several hundred bar.
Correct filling and venting of the hydraulic system are important for reliable operation.
Trapped gas should be minimized because its compressibility can affect pressure generation, settling time and system behavior.
Compatibility between the hydraulic medium and the device under test should always be checked before calibration.
Stainless Steel Calibration Masses
The BH2 series uses high-quality:
stainless steel calibration masses
The calibrated masses generate the gravitational force acting on the selected piston.
The generated reference pressure is therefore directly related to:
- Calibrated mass
- Local gravitational acceleration
- Effective piston area
- Relevant correction quantities
The mass set can be configured for different pressure units according to the customer’s requirements.
Available units include:
bar
psi
kPa
and other available engineering units.
Intermediate weight sets and additional basic weight sets for different units are also available.
Standard Gravity and Local Gravity
The force generated by a calibration mass depends directly on gravitational acceleration.
The conventional standard value is:
g = 9.80665 m/s²
However, local gravitational acceleration varies depending on geographical location.
The BH2-400B DP can therefore be configured according to:
standard gravity
or:
a customer-specific gravity value
For high-accuracy pressure calibration, using the correct gravity value is important because it directly influences the force applied to the piston.
Optional Motorization – OP0004
The europascal BH2-400B DP can be expanded with option:
OP0004
This option provides:
- Motorized rotation of the masses
- Piston position visualization
- LED indication
- Increased operator convenience
- Improved support during repetitive calibration procedures
Rotation helps minimize friction effects between piston and cylinder and supports stable piston operation.
The position visualization helps the operator determine whether the piston is within its correct working position.
Optional Calculator Module – OP0301
For laboratories requiring greater automation, the BH2-400B DP can be equipped with:
OP0301
This option adds:
- Motorization
- Dynamic piston position visualization
- Sensors
- Calculator module
- Automatic pressure calculation
- Automatic display of generated pressure
- Environmental parameter consideration
- Calibration data traceability
- Computer data transfer
- Support for calibration certificate generation
This transforms the conventional BH2 pressure balance into a significantly more automated calibration system.
It is particularly useful for laboratories performing frequent calibrations where manual calculations and documentation would otherwise require additional operator time.
Technical Highlights
Model: europascal BH2-400B DP
Device type: Hydraulic Dual Piston Deadweight Tester
Product family: BH2 High Performance
Configuration: Dual piston
Number of pistons: 2
Low-pressure range: 1 to 60 bar
High-pressure range: 5 to 400 bar
Overall pressure coverage: 1 to 400 bar
Low-pressure range: 10 to 800 psi
High-pressure range: 50 to 5,000 psi
Low-pressure range: 100 to 6,000 kPa
High-pressure range: 500 to 40,000 kPa
Maximum pressure: 400 bar / 40 MPa
Accuracy: 0.01 %
Measurement principle: Piston gauge / deadweight tester
Pressure medium: Oil
Number of weight sets: One common weight set for both piston ranges
Calibration masses: Stainless steel
Standard gravity: 9.80665 m/s²
Motorization: Optional
Automatic pressure calculation: Optional
Computer data transfer: Optional
Technical Data
| Feature | europascal BH2-400B DP |
|---|---|
| Manufacturer | europascal Aremeca |
| Model | BH2-400B DP |
| Device type | Hydraulic Dual Piston Deadweight Tester |
| Product family | BH2 High Performance |
| Configuration | Dual piston |
| Number of pistons | 2 |
| Low-pressure range | 1–60 bar |
| High-pressure range | 5–400 bar |
| Overall pressure coverage | 1–400 bar |
| Low-pressure range | 10–800 psi |
| High-pressure range | 50–5,000 psi |
| Low-pressure range | 100–6,000 kPa |
| High-pressure range | 500–40,000 kPa |
| Maximum pressure | 400 bar / 40 MPa |
| Accuracy | 0.01 % |
| Measurement principle | Piston gauge |
| Pressure medium | Oil |
| Calibration masses | Stainless steel |
| Weight sets | One set for both ranges |
| Standard gravity | 9.80665 m/s² |
| Special gravity | Available |
| Motorization | Optional – OP0004 |
| Piston position visualization | Optional |
| Automatic pressure calculation | Optional – OP0301 |
| PC data transfer | Optional – OP0301 |
BH2-400B DP vs. BH2-400B SP
The europascal Aremeca BH2-400B is available in two fundamentally different configurations:
BH2-400B DP – Dual Piston
and:
BH2-400B SP – Single Piston
The product described on this page is the dual-piston version.
| Feature | BH2-400B DP | BH2-400B SP |
|---|---|---|
| Configuration | Dual piston | Single piston |
| Number of pistons | 2 | 1 |
| Low-pressure range | 1–60 bar | — |
| High-pressure range | 5–400 bar | — |
| Single range | — | 2–400 bar |
| Overall coverage | 1–400 bar | 2–400 bar |
| Accuracy | 0.01 % | 0.01 % |
| Main advantage | Two optimized ranges | Simple single-piston operation |
The BH2-400B DP provides the advantage of two optimized piston-cylinder systems and extends the lower end of the measuring range down to 1 bar.
The BH2-400B SP provides simpler operation with only one piston-cylinder assembly.
The optimum configuration therefore depends on the pressure ranges and calibration workload of the laboratory.
BH2 High Performance Series
The europascal Aremeca BH2 series is designed as a family of high-performance hydraulic deadweight testers.
Dual-piston versions are available for several pressure ranges, including:
- BH2-300B DP
- BH2-400B DP
- BH2-600B DP
- BH2-700B DP
- BH2-1200B DP
These systems provide two pressure ranges using one common weight set.
Single-piston versions and higher-pressure BH2 models are also available.
This allows the appropriate pressure balance to be selected according to measuring range, required pressure medium, accuracy and calibration workflow.
Further europascal Aremeca products can be found here.
Calibration and Traceability
Regular calibration of both piston-cylinder assemblies and the calibration mass set is important for maintaining the metrological performance of the BH2-400B DP.
For dual-piston systems, both effective piston areas must be appropriately characterized because each piston represents an individual pressure-generating reference.
The measurement uncertainty budget should also consider relevant environmental and application-specific influence quantities.
The europascal calibration service provides professional calibration solutions for deadweight testers, pressure balances, pressure gauges, pressure sensors, pressure transmitters and other pressure measuring equipment.
europascal can also provide support with system configuration, maintenance and the selection of suitable pressure calibration equipment.
Why Choose the europascal BH2-400B DP?
The europascal BH2-400B DP Precise Dual Piston Deadweight Tester combines a broad overall measuring range from 1 to 400 bar with the flexibility of two optimized piston-cylinder systems.
The low-pressure piston covers 1 to 60 bar, while the high-pressure piston covers 5 to 400 bar. Both ranges are generated using the same calibration weight set.
With an accuracy of 0.01 %, the BH2-400B DP provides a reliable physical reference for demanding hydraulic pressure calibration.
Optional motorization, piston position visualization and automatic pressure calculation allow the system to be adapted to more advanced calibration workflows.
For professional laboratories requiring both low and medium-to-high hydraulic pressure calibration, the dual-piston concept provides an efficient alternative to operating multiple separate pressure standards.
Typical Calibration Applications with the europascal BH2-400B DP
The europascal BH2-400B DP is particularly suitable for calibrating precision pressure gauges, digital pressure gauges, hydraulic pressure gauges, pressure sensors, pressure transmitters, pressure transducers, pressure switches and other hydraulic pressure measuring instruments.
Typical application areas include professional calibration laboratories, pressure instrument manufacturers, industrial quality assurance, mechanical engineering, hydraulic systems, research and development and process instrumentation.
Looking for the europascal BH2-400B DP or a precise dual-piston pressure calibration solution from 1 to 400 bar? Contact europascal for expert advice, system configuration and professional calibration services tailored to your requirements.





