7250, 7250i, and 7250xi Pressure Controller / Calibrators
Key features
- Unique Quartz Bourdon Tube Pressure Sensor design provides high precision pressure measurement
- Available in custom Pressure ranges from 5 to 2500 psi
- Stable Pressure Control of 0.001 % FS.
- Cover wider pressure ranges with the 7250i or 7250xi with 0.005 % Reading measurement precision
Product overview: 7250, 7250i, and 7250xi Pressure Controller / Calibrators
Standard precision
The Fluke Model 7250 pressure calibrator / controller (formerly Ruska 7250) offers an economical approach to automatic pressure testing and calibration with a precision of 0.003 % of full scale for ranges to 2,500 psi (17.2 MPa). A 3,000 psi (21 MPa) full scale range is available with 0.012% of reading precision from 900 psi to 3000 psi (6.3 to 21 MPa) precision.
Models 7250xi and 7250i offer advanced percent of reading precision for increased capability with a single instrument, reducing the investment required to calibrate a wide variety of pressure devices and ranges.
The Model 7250xi provides 0.005 % of reading precision from 5 % to 100 % of the instrument's range. This unmatched precision is achieved through unique quartz pressure sensing technology and multiple quartz sensors in a single instrument. Various ranges from 0 to 20 and 0 to 2 500 psi (0 to 140 kPa and 0 to 17.2 MPa) are available.
The Model 7250i provides 0.005 % of reading from 25 % to 100 % of range and is available in various ranges from 0 to 5 and 0 to 2,500 psi (0 to 35 kPa and 0 to 17.2 MPa).
For pressure below the lower threshold of 5% for the 7250xi and 25 % for the 7250i, the precision becomes 0.005 % of the lower value. For example, a 1,000 psi (7 MPa) Model 7250xi provides 0.005 % of reading from 50 to 1,000 psi (0.035 to 7 MPa); the precision for pressures from 0 to 50 psi (0 to 0.035 MPa) is 0.005 % of 50 psi (0.035 MPa).
High-speed pressure control
All Series 7250 instruments up to 2,500 psi (17.2 MPa) reach setpoint in 20 seconds or less into a 15 cubic inch (245 cc) volume, with no overshoot, to allow high-speed pressure test and calibration.
Dual control modes
The Series 7250 also provides two user-selectable control modes: active and passive mode. In active mode, the 7250 is continually maintaining the setpoint and can compensate for small leaks and pressure changes due to temperature. In passive mode, the user defines a control band and the 7250 will turn off the controller once it achieves the setpoint within the control band. In a leak-free and temperature- stable system, passive mode contributes no additional uncertainty, providing optimum performance.
Automating pressure test and calibration
The 7250 is easy to use and can automate your calibrations in several ways:
Step up/down: for calibrations where the increments are fixed intervals, enter a userdefined step value. The Series 7250 increases or decreases the pressure by the step amount with the jog dial—no more lengthy keystroke sequences to program.
Sweep test: for simple exercising routines, as with dial gauges, enter a start value, a stop value, and number of times to repeat the cycle. The Series 7250 will automatically exercise the device under test prior to the calibration run.
Onboard programs: For frequently used or lengthy calibrations, the Series 7250 can store up to 20 user-defined programs/profiles with up to 1000 steps total in internal memory.
Computer interface: Every Series 7250 is provided with both an RS-232 and IEEE-488 interface, and Series 7250 syntax follows SCPI protocol for easy programming. A LabVIEW® driver is available as a free download. As a standard feature, software written for the previous generation Series 7215, 7010 and 6000 instruments is fully supported by the Series 7250. The Series 7250 can also be set to 510 emulation mode to use software originally written for the DPI 510. Firmware updates can also be performed over the RS-232 interface (updates can be downloaded from the web site). The 7250 series is compatible with COMPASS software.
Versatility to handle any pneumatic pressure calibration
The Series 7250 is versatile enough to handle almost any type of pneumatic pressure calibration.
Wide pressure range: available in a variety of standard or custom full scale pressure ranges from 5 to 3,000 psi (35 kPa to 21 MPa)
Pressure units/scales: Select from over twelve standard units of measure, including inHg at 0 °C and 60 °F, kPa, bar, psi, inH2O at 4 °C, 20 °C and 60 °F, kg/cm2, mmHg at 0 °C, cmHg at 0 °C, and cmH2O at 4 °C, and two user defined units.
Head pressure: Automatic correction for head pressure differences
Absolute mode: The 7250 offers three different methods to make absolute pressure measurements. The barometric reference option provides the most convenient method and is available on ranges 15 psi (1.0 bar) and higher. Alternatively, the vacuum reference option (not available on the 7250xi) allows the connection of an external vacuum pump to the reference port of the instrument. An onboard vacuum sensor monitors the reference vacuum and allows for automatic zeroing in absolute mode. This option provides the lowest overall uncertainty since it does not include the additional uncertainty of a secondary barometric reference sensor. For pressure to 50 psia (4 bar) permanent absolute models are also available.
Autovent and autozero: With few keystrokes, the Series 7250 will vent the test port to atmosphere or automatically zero itself (autovent is not applicable to permanent absolute models).
Protection of the device under test: Set upper and lower pressure limits to ensure protection of the device under test. ‘
Options
The Series 7250 can be provided for gauge mode operation, or with:
- Optional vacuum (negative gauge) mode for bidirectional devices
- Optional barometric reference for absolute mode calibrations
- Permanent absolute ranges to 50 psia (4 bar) full scale which include a tare feature for simulated gauge mode operation
- COMPASS® for Pressure
Specifications: 7250, 7250i, and 7250xi Pressure Controller / Calibrators
| Pressure Ranges | |
| Model 7250 | Any Full Scale pressure range from 5 to 2,500 psig (35 kPa to 17.2 MPa). Or, Permanent Absolute ranges from 15 to 50 psia (100 to 350 kPa). A 3,000 psia range (21 MPa) is also available. |
| Model 7250i | Any Full Scale pressure range from 5 to 2,500 psig (35 kPa to 17.2 MPa). Or, Permanent Absolute ranges from 15 to 50 psia (100 to 350 kPa). A 3,000 psia range (21 MPa) is also available. |
| Model 7250xi | Any Full Scale pressure range from 20 to 2,500 psig (138 kPa to 17.2 MPa). |
| Optional Modes | Absolute using barometric reference sensor for ranges from 15 to 2,500 psig (100 kPa to 17.2 MPa) Vacuum (negative gauge) for ranges 5 to 2,500 psig (35 kPa to 17.2 MPa) Vacuum reference (requires external vacuum pump) |
| Performance | |
| Precision | Model 7250 Ranges to 2,500 psi (17.2 MPa): 0.003% of FS 3,000 psi (21 MPa): 0.012% reading from 30% to 100% full scale. Below 30% FS: 0.00036% full scale Model 7250i From 25% to 100% full scale (FS): 0.005% reading Below 25% FS: 0.005% of 25% FS Model 7250xi From 5% to 100% full scale (FS): 0.005% reading Below 5% FS: 0.005% of 5% FS Precision is defined as the combined effects of linearity, repeatability and hysteresis throughout the operating. Expression of uncertainty conforms with the recommendations of the ISO Guide to the Expression of Uncertainty in Measurement. |
| Stability | Ranges up to 2,500 psi (17.2 MPa): 0.0075% of reading per year 3,000 psia (21 MPa) range: 0.005% of reading |
| Control Stability | Active mode: 0.001% FS (10 ppm) Passive mode: no additional uncertainty |
| Display Resolution | User selectable to 1:1,000,000 |
| Control Response | 20 seconds or less with zero overshoot into a 15 in3 volume (245 cc) for ranges to 2,500 psi (17.2 MPa) 60 seconds for 3,000 psia (21 MPa) range |
| Negative Gauge Precision (optional) | Model 7250 0.003% of FS Model 7250i 0.005% of 25% FS or 0.00075 psi (0.005 kPa), whichever is greater Model 7250xi 0.005% of 5% FS or 0.00075 psi (0.005 kPa), whichever is greater |
| Barometric Reference (optional) | 0.002 psi (0.014 kPa) maximum error per year |
| Vacuum Reference (optional) | 0.0002 psi (0.0014 kPa) maximum error per year (Only available on 7250i and 7250) |
| Calibration | |
| Calibration | An accredited calibration report is provided standard. |
| Total Uncertainty | |
| Maximum deviation from the true value of pressure including precision, stability, temperature effects and the calibration standard | |
| Model 7250 | Ranges to 2500 psi (17.2 MPa) 90 day 0.003% FS + 0.002% reading 1 year 0.003% FS + 0.0075% reading 3,000 psi (21 MPa) 30% to 100% FS 90 day: 0.012% reading 1 year: 0.013% reading |
| Model 7250i | Ranges from 25% to 100% full scale 90 day: 0.0055% reading 1 year: 0.009% reading |
| Model 7250xi | Ranges from 5% to 100% full scale 90 day: 0.0055% reading 1 year: 0.009% reading |
| Control Parameters | |
| Volume | 5 to 60 cubic inches (82 to 980 cc) |
| Low Control (absolute) | 0.15 psia (1 kPa) |
| Communications | |
| Communications | RS232 and IEEE-488, SCPI syntax. Series 7215, Model 7010, Series 6000 and DPI 510 emulation are standard. LabVIEW driver Firmware updates are performed via RS232 interface. |
| Languages | |
| Menus and functions | The Series 7250 is capable of displaying menus and functions in: English, French, Chinese, German, Japanese, Spanish and Italian. |
| Options | |
| Options |
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| General | |
| Display | TFT, VGA, active matrix, 6.4 in (162.5 mm) 640 x 480 resolution, 65,000 colors |
| Temperature | Operating: 64°F to 96°F (18°C to 36°C) Storage: -4°F to 158°F (-20°C to 70°C) |
| Humidity | 5% to 95% relative humidity, non-condensing |
| Dimensions | (h x w x d) All versions: 7 in x 16.5 in x 19 in (178 mm x 419 mm x 483 mm) |
| Weight | Model 7250/7250i: 17 lb (7.7 kg) Model 7250xi: 20 lb (9 kg) |
| Test Port and Supply Connection | 1/4 in NPT female |
| Warm Up Time | 2 to 3 hours; may be left on indefinitely |
| Pressure Medium | Nitrogen or clean dry air |