Fluke Calibration RUSKA 7252i is a versatile dual-output digital pressure controller designed for highly accurate and automated pneumatic pressure calibration over an exceptionally wide pressure range. With two independent pressure measurement and control channels, advanced quartz Bourdon tube pressure sensor technology and percent-of-reading performance, the 7252i combines high measurement performance with excellent calibration productivity.
Unlike conventional single-channel pressure controllers, the RUSKA 7252i incorporates two independent pressure ranges and two independent control channels. This architecture allows two pressure calibrations to be performed simultaneously. Alternatively, suitable ranges can be interconnected to provide exceptionally wide pressure range coverage for a single calibration workload.
Pressure configurations are available from very low differential pressures starting at 10 inH₂O (25 mbar) up to 2,500 psi (172 bar). The two installed ranges can be selected according to the required calibration workload.
For standard ranges from 5 to 2,500 psi (400 mbar to 172 bar), the RUSKA 7252i provides percent-of-reading performance. This makes the system particularly attractive for laboratories that need to cover a wide pressure range while maintaining excellent measurement capability.
The system uses proven quartz Bourdon tube pressure sensor technology, providing excellent stability, repeatability and long-term performance. Pressure control stability is specified at 0.001 % of each active range, while pressure changes can typically be controlled in 15 seconds or less under the manufacturer’s specified conditions.
At europascal, we provide professional pressure calibration solutions ranging from low differential pressure systems to high-pressure reference standards and fully automated calibration systems.
For professional calibration and metrological traceability of pressure controllers, pressure sensors and pressure measuring equipment, use the europascal Calibration Service.
Your Benefits at a Glance
- Dual-output digital pressure controller
- Two independent pressure measurement channels
- Two independent pressure control channels
- Two calibrations can be performed simultaneously
- Extremely wide configurable pressure range
- Low-pressure ranges starting at 10 inH₂O / 25 mbar
- Standard gauge ranges from 5 to 2,500 psi
- Maximum pressure up to 172 bar
- Percent-of-reading measurement performance
- Precision of 0.005 % of reading in the specified range
- Quartz Bourdon tube pressure sensor technology
- Long-term stability of 0.0075 % of reading per year
- Active control stability of 0.001 % of each range
- Fast pressure control
- Typical response of 15 seconds or less
- Zero overshoot under specified conditions
- Automatic range switching with suitable configurations
- Permanent absolute pressure ranges available
- Optional barometric reference
- Optional vacuum reference
- Optional negative gauge operation
- Automatic zeroing
- Automatic venting
- Automatic head pressure correction
- Step up/down calibration functions
- Automatic sweep testing
- More than fifteen standard pressure units
- RS-232 interface
- IEEE-488 interface
- SCPI command syntax
- LabVIEW driver available
- Optional MET/CAL driver
- Suitable for automated calibration laboratories
Two Independent Pressure Control Channels
The defining feature of the Fluke Calibration RUSKA 7252i is its dual-output architecture.
The instrument incorporates two independent pressure measurement and control systems.
Each channel can generate, control and measure its own pressure.
This means that two separate devices under test can be connected and calibrated simultaneously.
For calibration laboratories with high throughput requirements, this can provide a significant productivity advantage.
Instead of performing two calibration sequences consecutively, both can be operated at the same time.
Typical devices under test include:
- Mechanical pressure gauges
- Digital pressure gauges
- Pressure transmitters
- Pressure sensors
- Pressure transducers
- Pressure switches
- Portable pressure calibrators
- Pressure modules
Extremely Wide Pressure Range
The Fluke Calibration RUSKA 7252i provides exceptional flexibility when selecting pressure ranges.
Two ranges can be configured within one instrument.
Standard gauge pressure ranges are available from:
5 psi to 2,500 psi
or approximately:
400 mbar to 172 bar
Low-pressure configurations are also available starting at:
10 inH₂O
or:
25 mbar
This allows a single 7252i system to cover an exceptionally broad pressure workload.
For example, a system can combine a relatively low-pressure range with a much higher pressure range to match the specific calibration requirements of a laboratory.
Percent-of-Reading Performance
The Fluke Calibration RUSKA 7252i is the percent-of-reading version of the Series 7252.
For standard ranges from 5 to 2,500 psi, Fluke specifies precision of:
0.005 % of reading
over the specified upper portion of each installed range.
Below the applicable threshold, precision is based on the threshold value rather than the actual pressure reading.
This performance provides improved rangeability compared with the standard RUSKA 7252, which uses a percentage-of-full-scale specification.
The 7252i is therefore particularly suitable when a broad pressure range must be covered with excellent measurement performance.
RUSKA 7252i vs. RUSKA 7252
Fluke offers the Series 7252 in two main performance versions.
The RUSKA 7252i provides:
percent-of-reading performance
while the standard RUSKA 7252 provides:
0.003 % of full-scale precision for each installed range
The 7252i is therefore optimized for applications where excellent rangeability is particularly important.
Both models use the same basic dual-output architecture and provide two independent pressure control channels.
Quartz Bourdon Tube Pressure Sensors
The Fluke Calibration RUSKA 7252i uses precision quartz Bourdon tube pressure sensor technology.
Quartz provides excellent characteristics for high-accuracy pressure measurement, including:
- Excellent long-term stability
- High repeatability
- Low hysteresis
- High resolution
- Stable metrological performance
This sensor technology has been used throughout the RUSKA precision pressure product family.
Combined with the dual-range architecture, it enables the 7252i to provide excellent measurement performance over a wide pressure workload.
Two Calibrations at the Same Time
One of the major productivity advantages of the Fluke Calibration RUSKA 7252i is simultaneous pressure control.
Because both pressure channels operate independently, two separate calibration procedures can be performed at the same time.
For example, one channel could calibrate a lower-pressure instrument while the second channel calibrates a higher-pressure device.
This can significantly improve laboratory throughput when many pressure instruments must be calibrated.
The two-channel architecture is especially attractive for:
- Calibration service providers
- High-volume calibration laboratories
- Pressure instrument manufacturers
- Production testing
- Quality assurance departments
Interconnected Range Operation
For suitable range combinations, the two pressure channels of the RUSKA 7252i can also be interconnected.
Instead of performing two independent calibrations, the system can then use both installed ranges for one calibration workload.
The controller automatically changes between the lower and higher pressure sensors as required.
This provides excellent performance over a significantly wider pressure span.
It is particularly useful when one device under test has a very broad measurement range.
Fast Pressure Control
The Fluke Calibration RUSKA 7252i combines high measurement performance with fast automatic pressure control.
Under the manufacturer’s specified test conditions, each range can control pressure changes in:
15 seconds or less
for 10 % pressure increments into a 245 cm³ test volume.
The digital control valve technology is designed to reach the requested pressure without overshoot under these conditions.
Fast control reduces waiting time between calibration points and helps increase laboratory productivity.
Excellent Control Stability
Once the selected pressure has been reached, it must remain sufficiently stable for accurate measurement.
The Fluke Calibration RUSKA 7252i provides active control stability of:
0.001 % of each range
or:
10 ppm of full scale
In active mode, the controller continuously compensates for small pressure changes and minor leaks.
For systems where leakage has essentially been eliminated, passive control mode can be used.
In passive mode, the controller stops actively adjusting pressure within a user-defined band around the setpoint, allowing the pressure system to stabilize naturally.
Long-Term Stability
The RUSKA 7252i provides specified long-term stability of:
0.0075 % of reading per year
Long-term stability is especially important when the pressure controller is used as a reference standard in a calibration laboratory.
Stable sensor behavior helps maintain predictable measurement uncertainty between calibration intervals.
Regular calibration remains essential for maintaining metrological traceability.
Gauge Pressure Calibration
The Fluke Calibration RUSKA 7252i can be configured for gauge pressure calibration.
Gauge pressure configurations cover a broad range from low differential pressure up to:
2,500 psi / 172 bar
This makes the system suitable for calibration of a wide variety of industrial pressure instruments.
Typical applications include:
- Pressure gauge calibration
- Pressure transmitter calibration
- Pressure sensor calibration
- Pressure transducer calibration
- Pressure switch testing
- Portable calibrator testing
Permanent Absolute Pressure Ranges
Permanent absolute pressure ranges are also available.
Fluke specifies permanent absolute ranges from:
15 to 50 psia
or approximately:
1 to 4 bar absolute
These configurations are useful when absolute pressure calibration is the primary application.
Permanent absolute configurations provide direct absolute pressure measurement without relying on an additional barometric sensor.
Optional Barometric Reference
The Fluke Calibration RUSKA 7252i can be equipped with an optional barometric reference.
For suitable gauge pressure ranges, this allows absolute pressure to be calculated from the gauge pressure measurement and atmospheric pressure.
The barometric reference provides a convenient method for switching between gauge and absolute pressure calibration.
Fluke specifies a maximum barometric reference error of:
0.002 psi per year
or approximately:
0.138 mbar per year
This option is particularly useful for laboratories that regularly calibrate both gauge and absolute pressure instruments.
Optional Vacuum Reference
For applications requiring higher-performance absolute pressure measurement, a vacuum reference option is available.
An external vacuum pump is connected to the reference port.
This creates a vacuum reference for the pressure measurement system and avoids the additional uncertainty associated with a secondary barometric pressure measurement.
Fluke specifies a maximum vacuum reference error of:
0.0002 psi per year
or approximately:
0.014 mbar per year
The vacuum reference option is therefore particularly attractive for demanding absolute pressure calibration.
Negative Gauge Pressure
Optional negative gauge pressure operation is also available for the Fluke Calibration RUSKA 7252i.
This enables pressure calibration below atmospheric pressure.
Typical applications include:
- Compound pressure gauges
- Negative pressure transmitters
- Vacuum sensors
- Bidirectional pressure sensors
- Low-pressure instrumentation
This additional operating mode further increases the flexibility of the 7252i.
Automatic Step Up and Step Down
The Series 7252 provides convenient functions for automated multipoint calibration.
For calibrations using fixed pressure intervals, a user-defined step value can be entered.
The controller can then increase or decrease the pressure by the selected step.
This simplifies repetitive calibration sequences and reduces the amount of manual data entry required at each pressure point.
Automatic Sweep Testing
The Fluke Calibration RUSKA 7252i also supports automatic sweep testing.
The operator defines:
- Starting pressure
- Final pressure
- Number of cycles
The controller then automatically cycles the pressure through the defined sequence.
This is particularly useful for exercising mechanical pressure gauges before calibration.
Pressure cycling can also be useful for evaluating the repeatability and mechanical behavior of pressure instruments.
Automatic Zero and Vent Functions
The RUSKA 7252i provides automatic zeroing and venting functions.
With a few commands, the controller can:
- Vent the test port to atmosphere
- Perform automatic zeroing
- Prepare the pressure system for the next calibration sequence
These functions simplify routine laboratory operation.
Automatic venting does not apply in the same way to permanent absolute configurations.
Automatic Head Pressure Correction
Height differences between the pressure reference and device under test can cause measurable pressure differences.
The Fluke Calibration RUSKA 7252i therefore provides automatic head pressure correction.
This feature compensates for the pressure difference associated with the vertical distance between the reference level and the device under test.
Head pressure correction becomes increasingly important when working with low pressures and high measurement accuracy.
Protection of the Device Under Test
Upper and lower pressure limits can be defined in the RUSKA 7252i.
This helps protect the connected device under test against accidental overpressure or inappropriate negative pressure.
Pressure limits are particularly valuable when the installed pressure controller has a significantly higher range than the device being calibrated.
More Than Fifteen Pressure Units
The Fluke Calibration RUSKA 7252i supports more than fifteen standard pressure units.
Available units include:
- psi
- bar
- kPa
- inHg
- inH₂O
- kg/cm²
- mmHg
- cmHg
- cmH₂O
Different reference temperatures are available for certain liquid-column units.
The controller also supports:
two user-defined pressure units
This provides flexibility for specialized laboratory and industrial applications.
Automated Calibration Systems
The RUSKA 7252i is designed for integration into automated calibration systems.
Standard communication interfaces include:
RS-232
and:
IEEE-488
The instrument uses:
SCPI command syntax
for remote programming.
This allows calibration software to automatically:
- Select pressure setpoints
- Control pressure
- Monitor pressure stability
- Change pressure points
- Perform sweep sequences
- Record reference values
- Control automated calibration procedures
A LabVIEW driver is available, and a MET/CAL driver is offered as an option.
Pressure Medium
The Fluke Calibration RUSKA 7252i is a pneumatic pressure controller.
The specified pressure medium is:
Nitrogen or clean, dry air
Using clean pressure media helps protect the internal pressure sensors, control valves and pneumatic components.
Oil, water, particles and other contaminants should be prevented from entering the system.
A liquid trap assembly is available as an option for applications where contamination from devices under test may be a concern.
Large Color Display
The RUSKA 7252i features a:
6.4-inch TFT VGA active-matrix color display
with:
640 × 480 pixel resolution
and:
65,000 colors
Menus and operating functions are presented in plain text.
The user interface supports several languages, including English, German, French, Spanish, Italian, Chinese and Japanese.
Technical Highlights
The Fluke Calibration RUSKA 7252i combines two independent pressure controllers with percent-of-reading measurement performance:
- Dual-output digital pressure controller
- Two independent pressure measurement channels
- Two independent pressure control channels
- Simultaneous calibration of two devices
- Quartz Bourdon tube pressure sensor technology
- Standard gauge ranges from 5 to 2,500 psi
- Low-pressure ranges starting at 10 inH₂O
- Overall coverage from approximately 25 mbar to 172 bar
- Permanent absolute ranges available
- 0.005 % of reading precision in the specified range
- 0.0075 % of reading annual stability
- 0.001 % of each range active control stability
- Typical pressure control ≤15 seconds
- Automatic range switching with suitable configurations
- Optional barometric reference
- Optional vacuum reference
- Optional negative gauge pressure
- Automatic zeroing
- Automatic venting
- Automatic head pressure correction
- Step up/down functions
- Sweep testing
- RS-232
- IEEE-488
- SCPI commands
- LabVIEW support
- Optional MET/CAL driver
Technical Specifications
| Feature | Fluke Calibration RUSKA 7252i |
|---|---|
| Manufacturer | Fluke Calibration |
| Model | RUSKA 7252i |
| Device type | Dual Output Digital Pressure Controller |
| Sensor technology | Quartz Bourdon tube |
| Number of control channels | 2 independent channels |
| Standard gauge ranges | 5 to 2,500 psig |
| Standard SI range | 400 mbar to 172 bar gauge |
| Low-pressure ranges | Starting at 10 inH₂O / 25 mbar |
| Permanent absolute ranges | 15 to 50 psia / 1 to 4 bara |
| Precision | 0.005 % of reading in specified range |
| Annual stability | 0.0075 % of reading |
| Active control stability | 0.001 % of each range |
| Control response | Typically ≤15 seconds |
| Display resolution | Selectable up to 1:1,000,000 |
| Barometric reference | Optional |
| Vacuum reference | Optional |
| Negative gauge | Optional |
| Pressure medium | Nitrogen or clean, dry air |
| Test connections | 1/4-inch NPT female |
| Communication | RS-232 and IEEE-488 |
| Remote protocol | SCPI |
| Display | 6.4-inch TFT VGA |
| Operating temperature | 18 °C to 36 °C |
| Storage temperature | −20 °C to +70 °C |
| Dimensions | 178 × 419 × 483 mm |
| Weight | Approx. 9 kg |
| Power | 90–260 VAC, 50/60 Hz, 150 W |
| Warm-up time | 2–3 hours |
Why Choose the Fluke Calibration RUSKA 7252i?
The Fluke Calibration RUSKA 7252i provides a unique combination of measurement performance, rangeability and calibration productivity.
Its two independent pressure control channels distinguish it from conventional single-output pressure controllers.
Two devices can be calibrated simultaneously, allowing calibration laboratories to increase throughput without installing two completely separate pressure controller systems.
Alternatively, suitable pressure ranges can be interconnected to provide excellent measurement performance over a very broad pressure workload.
The available pressure configurations extend from low-pressure ranges beginning at 10 inH₂O / 25 mbar up to 2,500 psi / 172 bar.
The 7252i’s percent-of-reading performance further improves its rangeability compared with the standard 7252.
Quartz Bourdon tube pressure sensor technology provides excellent repeatability and long-term stability, while automatic pressure control reduces operator workload during multipoint calibrations.
Active pressure control stability of 0.001 % of each range and fast control response of typically 15 seconds or less support efficient, repeatable calibration procedures.
Options for permanent absolute pressure, barometric reference, vacuum reference and negative gauge operation allow the system to be configured for a wide variety of pressure calibration requirements.
RS-232 and IEEE-488 interfaces with SCPI commands make the controller suitable for integration into automated calibration systems.
For calibration laboratories and pressure instrument manufacturers requiring high throughput, broad pressure coverage and excellent measurement performance, the RUSKA 7252i provides a highly flexible pneumatic pressure calibration platform.
At europascal, we can assist you in selecting the appropriate RUSKA 7252i pressure range combination, operating mode, pressure connections and accessories for your individual calibration requirements.
For professional calibration and metrological traceability of pressure controllers, pressure gauges, pressure transmitters and other pressure measuring equipment, use the europascal Calibration Service.
Discover more Fluke Calibration products here.
Manufacturer information about the Fluke Calibration RUSKA 7252i is available on the official Fluke Calibration 7252/7252i product page.
