Selecting and deploying pressure sensors in mining, aerospace, and other harsh environments. Covers technology choice, media compatibility, thermal compensation, hazardous-area certification, and the field practice that protects long-term reliability.
What’s Covered
Why “extreme” requires a different specification approach
A pressure transmitter that meets its accuracy class on the bench may produce unreliable data on a haul truck or in an aircraft hydraulic loop. Extreme environments compound stress factors, temperature gradient, shock, vibration, EMI, and chemical exposure, and small specification gaps become unrecoverable failures in the field.
Durham Instruments stocks pressure transmitters and transducers from leading OEMs across the industrial and submersible pressure portfolio, including industrial, intrinsically safe, and explosion-proof variants for hazardous-area work. Browse the full pressure sensor catalog.
Pressure sensor technologies
| Technology | Strength | Common limits |
|---|---|---|
| Piezoresistive (silicon strain gauge) | High accuracy, broad range, mature technology | Temperature compensation needed; chip exposure to media must be managed |
| Bonded foil strain gauge | Robust at high pressure and rugged environments | Larger, lower bandwidth than piezoresistive |
| Capacitive | Excellent low-pressure accuracy and stability | More sensitive to vibration and EMI |
| Thin-film / sputtered | Long-term stability, fatigue resistance, hydraulic environments | Capital cost |
| Piezoelectric | Dynamic / transient pressure events | No DC response, not for static pressure |
For hydraulic and pneumatic system measurement at industrial pressures, sputtered thin-film and bonded foil designs dominate because they tolerate cyclic loading and overpressure events that would damage thinner technologies.
The five environmental factors that matter most
-
Temperature range and thermal gradient
Specify both the operating temperature range and the rate of temperature change. A sensor stable at 80 °C steady-state may produce significant transient error during a rapid 50 °C swing. Insist on temperature-compensated devices for outdoor and high-thermal-cycle applications.
-
Media compatibility
Confirm wetted materials against fluid chemistry. 316L stainless is the industrial default; titanium, Hastelloy, and PTFE diaphragms cover more aggressive media. Get a material certificate where the application demands it.
-
Mechanical shock and vibration
Mining and mobile equipment expose sensors to continuous vibration and frequent shock events. Specify shock and vibration ratings explicitly and avoid extending cables in ways that propagate vibration into the connector.
-
Ingress protection
IP67 is the working minimum for outdoor and washdown applications. IP68 is appropriate for submerged level transducers designed specifically for hydrostatic level work.
-
Electromagnetic environment
Industrial sites have substantial EMI from drives, welders, and switchgear. Use shielded cable, route away from power conductors, and prefer 4–20 mA outputs over voltage where the cable run is long. Pair with proper signal conditioning, especially in plants with documented ground noise.
Hazardous-area certification
Mining, oil and gas, and process plants frequently classify zones as potentially explosive atmospheres. Two certification approaches dominate:
- Intrinsically safe (IS), energy in the circuit is limited so that no spark or surface temperature can ignite the atmosphere. Requires IS-rated barriers and approved wiring practices.
- Explosion-proof (XP) / flameproof, robust enclosure contains any internal ignition. Heavy housings; suitable for fixed installations.
Industrial pressure transducers from current OEM partners are available in both IS and XP variants suitable for Class I Div 1 and similar classifications. Confirm the applicable approval (CSA, FM, ATEX, IECEx) against the jurisdiction of the installation.
Approval is jurisdiction-specific. A device certified ATEX for European installation is not automatically approved for North American Class/Division systems. Verify the approval matches the local code before procurement.
Installation patterns that protect reliability
- Mount the sensor with the diaphragm protected from direct impingement of particulate-laden flow
- Use a pulsation snubber or isolator on hydraulic systems with valve events
- For high-temperature media, specify a remote diaphragm or extended capillary to keep electronics within rated range
- Provide a service loop in cabling and clamp the cable to a stable surface
- For submerged level transducers, install with the vent tube routed to a dry, sealed location to maintain accurate reference
- Verify zero against atmospheric pressure on installation and document it
Applications: mining and aerospace
Mining
Mining applications combine high vibration, dust, water exposure, hazardous-area classification, and frequent thermal cycling. Sensors with welded-isolated diaphragms, IP68 ratings, IS or XP certification, and 4–20 mA output are the baseline. Spare strategy matters as much as initial selection, lead-time exposure for replacement units in remote mining locations can be the dominant cost.
Aerospace
Aerospace pressure measurement requires tight accuracy, low mass, qualification to vibration and shock standards, and full traceability. Hydraulic system pressures, pneumatic control loops, fuel system measurement, and flight test instrumentation each have specific qualification requirements. Documentation and configuration control are typically as demanding as the technical specification.
Browse current models in the pressure sensors & transmitters catalog, including industrial pressure transducers, submersible level transducers, and precision OEM devices.
FAQ
Should I choose 4–20 mA, voltage, or digital output?
4–20 mA is the industrial workhorse for long cable runs and noisy environments, it tolerates EMI better than voltage and is supported by virtually every PLC and DAQ. Voltage is appropriate for short, controlled cable runs. Digital outputs (HART, Modbus, IO-Link) provide diagnostics and configuration but add complexity at the host end.
How do I size pressure range?
Pick a full-scale range such that your normal operating pressure lies between 30% and 80% of full scale, with a comfortable margin to the safe overpressure limit. Over-ranging the sensor wastes resolution; under-ranging risks damage.
What is the difference between gauge, absolute, and sealed-gauge pressure?
Gauge references atmosphere, the most common industrial choice. Absolute references vacuum and is used where atmospheric variation matters (altimeters, vacuum systems). Sealed-gauge references a fixed sealed pressure and suits submerged or high-altitude applications where atmospheric reference is impractical.
Can pressure sensors handle hot media directly?
Up to a limit. For media above the sensor’s operating range, use a remote diaphragm with capillary, an extended cooling tower, or a heat-sinking mounting block. Direct mounting in steam or hot oil shortens sensor life and degrades accuracy.
Does Durham Instruments help with hazardous-area approvals?
Yes. Durham Instruments supplies pressure transducers in IS and XP variants and provides selection guidance against CSA, FM, ATEX, and IECEx requirements. Send your area classification and we will recommend approved options.
Pressure measurement in a harsh environment?
Send your operating envelope, media, and area classification. Our team will recommend a sensor, conditioning, and installation plan that holds up in the field.