Fluke 718Ex Intrinsically Safe Pressure Calibrator
The Fluke 718Ex is a self-contained intrinsically safe pressure calibrator designed specifically for calibration and troubleshooting tasks in explosion-hazardous areas.
Unlike a conventional pressure calibrator, the 718Ex combines an internal pressure/vacuum pump with pressure measurement and 0–24 mA current measurement, allowing technicians to test pressure transmitters and related instrumentation without carrying separate pressure and current instruments.
Intrinsically Safe for Hazardous Areas
The most important characteristic of the Fluke 718Ex is its certification for use in hazardous environments.
It is compliant with:
ATEX II 1G Ex ia IIC T4
CSA Class I, Division 1, Groups A–D, T4
Intrinsically safe design for applicable hazardous-area applications
This makes the 718Ex suitable for process facilities where potentially explosive gases or vapors may be present.
Built-In Pressure and Vacuum Pump
The 718Ex includes a built-in pressure/vacuum hand pump, eliminating the need for a separate pressure source for many field calibration tasks.
The integrated pump includes:
Fine-adjustment vernier
Bleed valve
Pressure generation
Vacuum generation
Self-contained operation
The built-in pump can generate pressure from approximately -820 mbar to the selected full-scale range and is intended for use with non-corrosive gases.
Three Pressure Ranges
The Fluke 718Ex is available in three internal pressure ranges:
718Ex 30G: up to 2 bar / 30 psi
718Ex 100G: up to 7 bar / 100 psi
718Ex 300G: up to 20 bar / 300 psi
The internal pressure sensor provides 0.05% of full-span accuracy.
Key Pressure Specifications
Internal pressure accuracy: 0.05% FS
Vacuum capability: approximately -830 mbar
Built-in pump source: approximately -820 mbar to full scale
Pressure units: psi, bar, mbar, kPa, inH₂O, cmH₂O, kg/cm², mmHg, inHg and others
Functions: Zero, Min, Max, Hold and Damp
Pressure switch test function
Extended Pressure Measurement with 700PEx Modules
For applications requiring pressure ranges beyond the internal sensor, the Fluke 718Ex can be connected to Fluke 700PEx intrinsically safe pressure modules.
Depending on the module, pressure measurement can be extended up to 200 bar / 3000 psi. Fluke lists a broad range of compatible pressure modules, with module-dependent accuracy available down to 0.025% of full span.
This makes the 718Ex suitable for both low-pressure calibration and higher-pressure transmitter testing.
4–20 mA Current Measurement
The Fluke 718Ex is not only a pressure instrument. It also provides 0–24 mA current measurement, allowing technicians to verify the electrical output of pressure transmitters while applying a known pressure.
Important electrical specifications include:
Current range: 0–24 mA
Resolution: 0.001 mA
Accuracy: 0.02% of reading ±2 counts
Simultaneous pressure and current display
5-digit pressure/current LCD display
This combination is particularly useful for checking whether a pressure transmitter correctly converts applied pressure into its expected 4–20 mA output.
Pressure Transmitter Calibration
The Fluke 718Ex can be used for calibration and verification of pressure transmitters by applying a controlled pressure while monitoring the transmitter's current output.
Typical workflow:
Generate pressure → Measure pressure → Measure 4–20 mA output → Compare transmitter response
This makes it useful for:
Pressure transmitter calibration
Pressure transmitter troubleshooting
Zero and span verification
4–20 mA output testing
Field commissioning
Preventive maintenance
Pressure Switch Testing
The integrated pressure switch test function allows technicians to determine switch activation and reset behavior.
This can be useful for verifying:
Pressure switch set point
Reset point
Switching behavior
Process protection devices
The instrument also provides Min/Max Hold functions for capturing changing measurement values.
Field-Oriented Design
The 718Ex is designed for portable field work, with a compact housing and straightforward push-button operation.
Key mechanical specifications include:
Dimensions: 216 × 94 × 66 mm with holster
Weight: approximately 992 g with holster
Operating temperature: -10 °C to +55 °C
Storage temperature: -40 °C to +60 °C
Maximum operating altitude: 3000 m
Battery: one 9 V alkaline battery
Warranty: 3 years; 1 year for pump
Drop test: 1 m
Typical Applications
Oil & Gas
Pressure transmitter calibration
Wellhead instrumentation
Process pressure monitoring
Hazardous-area instrument maintenance
Chemical & Petrochemical
Pressure switch testing
Pressure transmitter verification
4–20 mA loop testing
Process instrument commissioning
Pharmaceutical & Process Plants
Pressure measurement verification
Transmitter calibration
Instrument troubleshooting
Preventive maintenance
Hazardous-Area Instrumentation
The 718Ex is particularly suited to applications where technicians require a portable pressure calibrator with intrinsic safety certification rather than a standard non-Ex calibrator.
Fluke 718Ex vs. Standard Fluke 718
The major difference is the hazardous-area certification and intrinsically safe design.
The Fluke 718 is a standard pressure calibrator, while the 718Ex is specifically designed and certified for applicable explosive atmospheres.
Therefore:
Fluke 718 → Standard pressure calibration
Fluke 718Ex → Intrinsically safe pressure calibration for hazardous areas
For an installation requiring certified intrinsically safe equipment, the 718Ex should be selected according to the applicable hazardous-area classification and certification requirements.
FAQ
Q: What is the Fluke 718Ex used for?
A: It is used for pressure calibration, pressure transmitter testing, pressure switch testing and 4–20 mA measurement in applicable hazardous areas.
Q: Is the Fluke 718Ex intrinsically safe?
A: Yes. It is certified ATEX II 1G Ex ia IIC T4 and also carries CSA Class I, Division 1 certification for Groups A–D, T4.
Q: Does the Fluke 718Ex have a built-in pressure pump?
A: Yes. It has an integrated pressure/vacuum hand pump with fine adjustment and a bleed valve.
Q: What pressure ranges are available?
A: The internal sensor versions are 30 psi, 100 psi and 300 psi, corresponding to approximately 2, 7 and 20 bar full-scale pressure.
Q: Can the Fluke 718Ex measure 4–20 mA?
A: Yes. It measures 0–24 mA with 0.001 mA resolution and 0.02% reading accuracy plus 2 counts.
Q: Can the pressure range be extended?
A: Yes. Compatible intrinsically safe Fluke 700PEx pressure modules can extend pressure measurement up to 200 bar / 3000 psi, depending on the module.
