Accurate pressure readings start long before a sensor is powered up: they depend on choosing the right device, mounting it in the right place, and protecting it from heat, vibration, trapped air, condensate and electrical noise. We recognise that if a reading drifts or spikes after installation, you can lose time checking the process, questioning the instrument, or making control decisions on unreliable data.
This guide from Diversified Technologies sets out practical pressure sensor installation best practices so you can improve reading stability and reduce avoidable faults from the outset. We cover selection, process connections, pipe location, tap orientation for gases and liquids, steam and high-temperature applications, impulse lines, wiring, grounding, calibration and troubleshooting. Our aim is to help you think through the conditions around the sensor, not just the sensor specification, so your installation supports the accuracy your system needs.
- Accurate pressure readings depend on proper sensor selection, mounting, process connections, wiring, grounding, calibration and commissioning discipline.
- Choose the sensor before installation by matching pressure range, accuracy, reference type, wetted materials, temperature limits and overpressure conditions.
- Mount sensors in stable pipe zones away from elbows, valves, pumps and reducers to reduce turbulence, pulsation and local pressure distortion.
- Gas pressure taps usually belong on top of the pipe so condensate, oil or other liquids do not collect in the measurement path.
Why proper pressure sensor installation matters
Reliable readings depend as much on how the sensing element is fitted as on its datasheet. A well-specified device can still drift, spike or read low if the tap, wiring, mounting angle or impulse tubing is wrong. In practice, accurate measurement starts with mechanical, electrical and commissioning discipline before any calibration certificate is trusted.
At Diversified Technologies, we treat site fitting as a measurement-control task, not a final assembly step. The reason is simple: most accuracy claims are made under defined reference conditions, while real plant adds vibration, heat, trapped air, condensation, electrical noise and flow turbulence. That said, a sensor with ±0.25% full-scale accuracy can deliver much poorer process data if it’s mounted on a vibrating bracket, connected through a partially blocked line, or powered by an unstable 4-20mA loop.
In short, calibration can’t fully correct a poor mechanical fit.
According to API RP 551, process measurement systems should allow safe isolation, venting and checking of instruments without compromising the process. That matters on site because verification is only meaningful when the transmitter, manifold, tubing and process connection behave as a single system. ISA and IEC guidance follows the same engineering logic too: keep the instrument’s surroundings under control, reduce avoidable uncertainty, and document the set-up so another technician can review it later. BD Sensors model manuals and datasheets should be checked before work starts, particularly for wetted materials, electrical limits, diaphragm seal handling, output type and process connection torque.
| Risk | Reading effect | Control measure |
|---|---|---|
| A tap is placed too close to a pump, valve or elbow. | The measured value may fluctuate because the sensing point is in disturbed flow. | Select a calmer pipe zone and record the upstream and downstream conditions. |
| Impulse tubing is routed with pockets that trap gas or liquid. | The transmitter may show offset, lag or unexplained drift during normal operation. | Use continuous slope, suitable supports and correct vent or drain orientation. |
| Signal cabling runs beside high-power drives or switching loads. | The output may show noise that looks like real process variation. | Separate cable routes, apply shielding correctly and verify the loop under load. |
| A diaphragm seal is over-tightened or exposed to handling damage. | The sensing face may deform and introduce a permanent measurement error. | Follow the manufacturer’s tightening method and protect the membrane until commissioning. |
A useful pre-work checklist should still cover the basics: LOTO status, media compatibility, range, accuracy class, process thread, gasket or seal type, mounting position, impulse tube route, wiring method and verification equipment. For high-integrity work, that checklist should be printable and retained with the job pack, alongside wiring sketches for the selected signal type and any PDMS tag references used by the asset system.
Electrical detail deserves the same attention as pipework. According to IEC 61000-series electromagnetic compatibility principles, immunity depends on the complete arrangement, including segregation, bonding, shielding and earthing practice. A HART device may communicate correctly on the bench yet fail in the field if loop resistance, power supply headroom or shield termination is wrong. Likewise, IO-Link and digital transmitters reduce analogue scaling errors, but they don’t remove errors caused by blocked taps, thermal stress or poor grounding.
First, confirm LOTO, depressurisation and media hazards before loosening any fitting. Next, review the datasheet for range, output, overload limit, wetted parts and torque guidance. Then, check the sensing point for vibration, temperature, accessibility and stable flow conditions. After that, inspect tubing, manifolds, seals and cables before energising the instrument. Finally, complete zeroing, span verification and a documented as-found/as-left record during pressure transmitter commissioning.
What you want at handover is a reading that can be defended: the device is correctly selected, mechanically sound, electrically quiet and verified against the pressure measurement accuracy specs claimed for the application.
Choose range, accuracy, and media compatibility
Before installation, match the pressure sensor to the process pressure range, required accuracy, pressure reference, wetted materials, temperature limits, and maximum overpressure. The two checks below run in parallel: get the range and reference right, and get the accuracy and materials right for the medium.
Start with range and reference
A good starting point is the normal operating band: note any expected spikes, vacuum or compound duty, overpressure margin and burst rating; then compare gauge, absolute and differential references against the control task. Oversizing wastes useful resolution, while undersizing can damage the sensing element and create drift.
Then accuracy and media compatibility
Accuracy is not one number. Published sensor specification guidance breaks it into several contributors: temperature coefficients, temperature hysteresis, pressure hysteresis and non-linearity, alongside resolution, long-term stability and process temperature compensation. For media compatibility, match the fluid or gas to wetted materials, seals, corrosion risk, clogging potential, sanitary or hazardous-area requirements, IP rating and fitting style.
If pulsation is likely, add snubber selection or a bleed valve to the installation checklist before field calibration.
Send us the process data rather than just the part number, and our engineers will check range, reference, wetted materials, connection style and mounting against the duty before anything is ordered.
Selecting the right process connection and mounting method
Reliable readings start with a mechanical fit that matches the medium, pipework and maintenance routine. Before wiring or calibration, lock down the process connection, sealing method and mounting position so the instrument measures the process itself, not stress from the installation.
- Confirm the process conditions before choosing the connection. Record the measurement range, maximum temperature, wetted-material compatibility, cleaning regime and whether the line carries gas, liquid, steam, slurry or corrosive media; according to IEC 60529, the IP rating describes enclosure protection against dust and water, not chemical resistance or process sealing.
- Match the connection style to the application rather than defaulting to the smallest thread. Use the table below as a site checklist before you approve the drawing, and keep a marked-up copy with the installation pack for future maintenance.
| Connection option | Best use | Installation note |
|---|---|---|
| A threaded port suits compact machinery, hydraulic power packs and OEM panels. | Use it where vibration is under control and the port can support the transmitter body. | Apply the specified sealant or gasket only to the sealing area, because excess tape can enter the line. |
| A flanged connection suits larger pipes, high-energy services and planned shutdown maintenance. | Choose it when bolting load, gasket choice and alignment can be controlled. | Tighten bolts in a cross pattern and avoid using the instrument as a lever during alignment. |
| A sanitary connection suits food, beverage, pharmaceutical and clean-in-place duties. | This is the right fit when crevice-free wetted surfaces and quick removal matter. | Use the correct clamp gasket and surface finish for a sanitary installation. |
| A remote seal or capillary assembly suits hot, viscous, crystallising or aggressive media. | Use it when direct mounting would put the electronics in harm’s way. | Follow remote mounting guidelines and keep capillaries protected from sharp bends and temperature gradients. |
- Choose a mounting method that isolates the device from pipe strain. Support heavy transmitters with a bracket, keep the body accessible for calibration, and allow enough clearance for a bleed valve, manifold handle or electrical connector.
- Plan pulsation control before the first start-up. For pumps, compressors and fast-acting valves, select a snubber, damper or restrictor that slows spikes without hiding real process changes; poor snubber selection can create delayed readings that look like drift causes.
- Orient the unit so trapped air, condensate or solids cannot sit on the diaphragm. A liquid service usually needs the port below or level with the tapping point, while gas service usually benefits from a take-off that lets condensate drain away.
- Check the mechanical installation before zeroing. Loosen no live fittings, follow your lockout/tagout procedure, vent safely through the manifold or bleed point, then record the as-mounted zero offset so later technicians can distinguish installation bias from genuine pressure sensor drift causes.
- Verify the output format against the mounting environment. A 4-20 mA loop, HART device, IO-Link unit or digital transmitter may all read correctly on the bench, but connector orientation, ingress protection and cable strain relief decide whether the signal remains stable after washdown or vibration.
The step most often treated too casually is mechanical support: a transmitter should not be used to carry pipe load or correct misalignment. If the connection is square, sealed and strain-free, accurate readings become much easier to prove during calibration.
Place the sensor in a stable pipe zone
A pressure sensor should sit in a straight, stable section of pipe, away from elbows, valves, pumps, reducers, and other turbulence sources. For more accurate readings, use a developed-flow zone where fittings won’t distort the profile, cause pulsation, or create local high and low zones at the sensing face.
A widely used rule of thumb for transducer installation is to position the tapping point 10 pipe diameters downstream and 5 diameters upstream from bends, valves, restrictions, or similar disturbances. The port shouldn’t face direct impingement, sit in a dead leg, or turn into a debris trap.
- Confirm access for isolation valves, a bleed valve, leak checks, safe removal, and field calibration certificate work.
- Use a sensor mounting bracket where vibration or pipe strain could load the connection.
- For differential applications, route matched impulse lines with equal length, consistent fall or rise, and planned elevation correction.
A short installation checklist and torque chart can help protect the measurement accuracy specs during commissioning.
Gas pressure tap orientation
Gas pressure taps should usually be mounted on the top of the pipe so condensate, oil, or other liquids don’t collect in the sensing port or impulse line. That’s the default we use for gas service because trapped liquid can add hydrostatic head, delay response, plug the tapping, or make the signal hunt. Side taps are a controlled exception; bottom taps are rarely acceptable.
For a worked example, take a horizontal gas header feeding a burner train with a smart transmitter, a three-valve manifold, and an impulse tube installation running to a local panel. Before any mechanical work, the installer verifies isolation, depressurisation and lockout/tagout, then checks the transmitter manual, the project specification, and any applicable ISA, API or IEC requirements. Standard transmitter installation guidance for gas applications places taps in the top or side of the line and mounts the transmitter beside or above the taps so liquid drains back into the process piping.
The installation then becomes a sequence rather than a guess. In practice, the tapping is positioned away from elbows, valves and regulators where velocity profile and pulsation effects are worst. Second, the tubing is routed with a continuous fall back to the line for dry gas, or towards a condensate pot where wet gas must be drained under a defined maintenance procedure. Third, the manifold is mounted so vents and drains are usable without stressing the transmitter body. Finally, the loop is powered and checked; if a 4-20mA signal or HART value is noisy, we would review the tap and impulse route before treating the fault as wiring, grounding or sensor drift.
Wet gas changes the judgement. A top tap can still be correct, but the impulse line slope, low-point drains, freeze protection and access for inspection become part of the measurement design, not afterthoughts. A diaphragm seal may remove the impulse line altogether where fouling, corrosion or plugging risk is high, but the seal fill fluid and mounting elevation must then be assessed for temperature effects and zero shift.
Liquid pressure tap orientation
Liquid pressure taps should usually be mounted on the side of the pipe to reduce trapped air at the top and sediment buildup at the bottom. Standard transmitter installation guidance for liquid service is consistent on this point: side taps help keep solids out of the impulse path while allowing gas to return to the process line. For accurate readings, we favour side mounting with short, clean impulse runs.
What details make a side tap work properly?
Keep the impulse run as short and self-draining as the layout allows. In practice, add an isolation valve and a bleed valve where maintenance, LOTO checks, or commissioning zero tests require safe venting. For remote mounting, route tubing so it does not trap bubbles or transmit vibration into the instrument.
Are there exceptions to the side-tap rule?
Yes. Clean liquids, vertical pipework, sanitary pressure sensor installation, flush-diaphragm connections, or manufacturer-specific instructions can change the correct orientation. In hygienic designs, the priority may be full drainability and clean-in-place performance rather than a conventional side branch. Before signing off the detail, compare the mechanical layout with the instrument manual, the IP rating needs, process temperature compensation limits, and any ISA, API, or IEC practices used on the site.
Tap orientation at a glance
- Top of pipe: Preferred for a dry gas line, since liquid is least likely to settle in the port. What we’d still check is whether the tubing route lets any incidental condensate fall away safely.
- Side of pipe: It can make sense when a specific standard, manifold layout, or safe-access constraint requires it. The designer should check for partial liquid hold-up that could create a small zero offset.
- Bottom of pipe: Avoid it unless condensate drainage is intentional and the manufacturer approves the arrangement. The likely failure modes are blocked impulse tubing, slow recovery after trips, and unstable transmitter output.
- Top of pipe: Usually the weakest choice for liquids. Air or gas can collect there, adding compressibility that creates delayed, unstable, or low readings.
- Side of pipe: Best default choice for most liquid lines. The port is less exposed to gas pockets above and sludge, scale, or debris below.
- Bottom of pipe: Normally avoid this unless the design specifically requires it. Sediment can settle into the port and cause blockage, zero offset, or apparent drift.
We can help you choose between a siphon, cooling leg, diaphragm seal or remote mount, and check that every valve, manifold, seal and cable in the assembly is rated for the same duty.
Install for steam or high temperature
In steam or high-temperature service, keep the pressure sensor out of the direct heat path with a siphon, pigtail, cooling tube, diaphragm seal, or remote mounting method rated for the application. That keeps hot media away from the measuring cell, reduces thermal zero/span shift, and helps keep the electronics within the manufacturer’s stated limits.
Excessive process temperature is one of the most common pressure sensor drift causes: it can move zero and span, harden elastomer seals, damage cable glands, and shorten electronic component life. In saturated steam duty, the usual practice is to fit a pigtail or siphon so condensed water forms a protective barrier between the steam and the instrument. That loop must be filled before start-up, otherwise live steam can strike the sensing element during commissioning.
According to the BD Sensors DMP 331 datasheet, that specific model lists a maximum media temperature of 125°C and an ambient electronics limit of 85°C; those figures apply to that model, not every transmitter in the range. For hotter duties, check the exact datasheet, seal material, fill fluid, connector rating, cable specification, manifold rating, and impulse tubing limit as one system. In practice, the weakest component sets the safe operating boundary.
The isolation method needs to suit the medium and temperature: a siphon or pigtail is normally used for steam, while a cooling tube, diaphragm seal, or remote mount is used where heat soak remains excessive. The transmitter body should be kept away from hot metalwork: mount it clear of radiant heat from boilers, jackets, trace-heated pipework, and exhaust paths. Every accessory needs matching ratings: confirm the pressure and temperature limits for valves, manifolds, tubing, seals, connectors, and cable insulation. A compliant instrument can still fail if a small fitting is outside its envelope.
First, apply LOTO and depressurise the line before mechanical work begins. Next, install the siphon, pigtail, seal, or cooling leg in the orientation shown by the manufacturer. Then, prime steam loops with water, and open the process valve slowly to prevent thermal shock. After that, keep the electronics shaded from radiant heat and use the specified IP rating pressure transmitter connector for washdown or outdoor service. Finally, after warm-up, verify zero and record any pressure sensor zero offset against the calibration sheet.
Standards and good-practice references such as ISA instrumentation guidance, API piping practice, and IEC electrical requirements support the same principle: thermal protection is part of measurement integrity, not an optional accessory. If a snubber is also needed for pump ripple or valve chatter, make the pressure sensor snubber selection separately; pulsation damping does not replace heat isolation. In hygienic service, sanitary pressure sensor installation may require a flush diaphragm rather than an impulse line, because dead legs can create cleaning and contamination risks.
For digital outputs, including IO-Link or plant data systems, heat management still matters. A stable signal can’t correct a damaged diaphragm, degraded seal, or overheated circuit board. The best high-temperature assembly is one where process heat, ambient heat, component ratings, and start-up procedure are reviewed together before the line is returned to service.
Impulse lines, manifolds and tubing best practices
Accurate readings depend as much on the small pipework as on the transmitter itself: impulse lines must be short, supported, leak-tight and continuously sloped. A practical rule is a minimum fall or rise of 1:10 so gas can vent and liquid can drain; trapped bubbles or condensate can shift the measurement before any calibration begins.
In differential-pressure service, mount a three- or five-valve manifold close to the instrument, use equal-length tubing where possible, and keep bends gentle rather than flattened. IEC 61518 standardised manifold interfaces help reduce assembly errors between transmitters and valve blocks; API RP 551 also treats impulse piping layout as part of measurement quality, not just mechanical fitting. It’s worth checking the installation torque chart for fittings, applying the correct process connection torque, and documenting the tube route on a simple drawing or printable checklist. PDMS/IO-Link diagnostics can flag drift, but they can’t compensate for a poorly routed wet leg.
Route and ground wiring to reduce noise
Keep pressure sensor wiring away from motors, VFDs, contactors, high-voltage cables, and radio-frequency noise sources, using shielded cable where the manufacturer recommends it.
For a cleaner signal, keep instrumentation wiring separate from power wiring, terminate shields exactly as the sensor and control-system manuals require, and avoid any ground path that lets circulating current enter the measurement circuit. Even with good routing, EMI/RFI can still create noisy, drifting or offset signals, especially on millivolt bridge outputs and low-level voltage signals.
First, route signal cable in its own tray, conduit or segregated loom, not beside motor feeds, VFD output cables or solenoid wiring. If a power cable crossing is unavoidable, cross it at 90 degrees and keep the parallel run as short as the panel layout allows. Record the route on the commissioning sheet so later 4-20mA loop troubleshooting doesn’t start with guesswork.
Next, choose cable to match the output type. Use twisted screened pairs for analogue signals, check capacitance limits where HART transmitter wiring is used, and keep IO-Link or other digital outputs within the manufacturer’s topology rules. The BD SENSORS DMP 331 operating instructions put the supply polarity, load resistance and shield connection in the model wiring diagram and EMC notes, so we check those exact pages before energising.
Then, maintain shield continuity through glands, junction boxes and marshalling panels. Many analogue signal shields are bonded at one end only, usually at the control cabinet, because that reduces ground loops at mains frequency. Some installations bond both ends for high-frequency screening or equipotential safety, but that decision must come from the sensor manual, PLC or DCS guidance, and site earthing rules.
After that, ground the shield with a low-impedance termination, not a long pigtail curled inside the enclosure. At radio frequencies, a tidy tail can behave like an aerial and couple interference into a 0-10V signal. Bonding clamps, conductive glands and clean metal contact are often better than a spare terminal used as an afterthought. Finally, protect the cable mechanically at the transmitter. Fit strain relief so vibration from pumps, compressors or sensor pulsation damping devices doesn’t load the connector pins. Add a drip loop before the entry, use the specified IP-rated connector, and leave enough slack for calibration access without putting tension on the seal.
The detail installers most often get wrong is shield grounding, because earthing both ends can sound safer than it is on a sensitive analogue loop. Follow the documented diagram first, then record the termination in your printable checklist beside process connection torque and impulse tube notes.
Calibration, zeroing and verification after installation
Accurate readings after installation depend on proving the whole measurement chain, not just the device. Once the mechanical fitting and wiring are done, isolate the process, apply LOTO where required, vent safely, then set zero offset at true no-load or known reference conditions. Worth noting: this prevents mounting strain, trapped air and impulse-line head from becoming permanent error.
First, let the temperature settle for 10–15 minutes before adjustment; diaphragm seal installation may need longer because fill fluid expands. Next, check the 4-20mA signal at 4, 12 and 20 mA, then compare the control system value with a traceable calibrator. Then, for HART transmitter wiring or PDMS/IO-Link outputs, check that the device tag, range and damping match the datasheet, not just the display. Finally, record as-left results at 0%, 50% and 100%; according to IEC 61298-2, step tests help reveal hysteresis and non-linearity.
Oscillating readings are a cue to review sensor pulsation damping before changing calibration; damping masks dynamics but does not correct pipework disturbance. If zero shifts after valve operation, inspect process connection torque, impulse tube installation and manifold equalisation. Keep these checks in a printable commissioning sheet so verification stays consistent across technicians.
Troubleshoot noisy, drifting, or wrong readings
Start pressure sensor troubleshooting by separating the possible sources: process pressure, mechanical installation, wiring, configuration, and calibration. If readings are noisy, drifting, or clearly wrong after fitting, prove the actual pressure with a reference gauge first, then work through the mechanical, electrical and configuration checks before you adjust the instrument.
Here’s a typical commissioning example: a transmitter on a chilled-water skid is showing a fluctuating 4-20 mA signal, and the control system trend doesn’t match the operator’s local gauge. The first move is not recalibration. It is safe isolation: follow lockout/tagout, close the manifold or process valve, and depressurise before loosening any connection or removing the device.
- Compare the reading with a traceable reference gauge and the field calibration certificate.
- Inspect the process connection for leaks, blocked ports, clogged impulse tube work, sediment, trapped air in liquids, or trapped liquid in gas service.
- Review orientation, pipe location and straight run, especially near pumps, elbows, control valves and pulsating flow.
- Check whether vibration, radiant heat, mounting stress or process connection torque is outside the maker’s guidance or torque chart.
- Inspect power, shielding, grounding and the wiring diagram for 4-20 mA and HART circuits.
- Confirm range, units, damping, zero, span, output scaling and control-system tag mapping before you recalibrate.
A noisy signal appears on the trend after start-up: EMI, poor shielding, pump pulsation or an unstable pipe zone may be disturbing the output. Review grounding against IEC 61326-1 principles, then compare the signal with a local gauge and damping settings. The zero point moves gradually during operation: heat, overpressure, mounting stress, moisture ingress or normal ageing is changing the sensing element. Check ambient and media temperature, the mounting bracket, ingress marks and the latest calibration record. The value is consistently wrong but stable: a range/output mismatch, wrong engineering units or trapped head pressure is biasing the measurement. Match the datasheet range to the PLC scaling and review the pressure measurement accuracy specs.
Manufacturer diagnostic guidance, including BD SENSORS operating instructions where supplied, usually points you back to the same discipline: match the visible symptom to probable causes and corrective action before changing parts. That approach also aligns with ISA-style instrumentation best practices: verify the process, then the installation, then the signal chain. For the paperwork, a printable commissioning checklist should mirror this order so a technician records the reference reading, wiring checks, configuration values and final as-left result in one place.
Incorrect readings after commissioning are most often fixed by proving the process first, then checking mechanics, wiring, scaling and calibration in that order.
Stop troubleshooting and replace the instrument if the diaphragm is damaged, there has been a confirmed overpressure event, corrosion is visible, water has entered the housing, or the unit can’t pass calibration against its stated specification.
Contact Diversified Technologies for installation and sensor selection support
Your final selection review should check the sensor, mounting hardware and commissioning method as one system, not as separate parts. In practice, pressure measurement accuracy specs only hold when the range, media compatibility, wiring, process connection torque and zero verification match the application.
At Diversified Technologies, we treat this as a documentation check as much as a product choice: the most useful evidence is a completed one-page checklist covering LOTO status, sensor mounting bracket, impulse tube routing, diaphragm seal suitability and the required torque value from the relevant manual. According to IEC 60770, transmitter performance testing depends on defined reference conditions; that’s why a ±0.25% FS device can still give poor readings if the field setup is wrong. Bring the process data, not just the part number.
Speak with a Diversified Technologies engineer on 585-461-2110 for help with sensor selection, mounting hardware, impulse line design and commissioning documentation.
Frequently Asked Questions
Excess sealant, tape fragments, and incorrect thread engagement can block the pressure port or stress the sensing body, creating offset errors even when the sensor is correctly specified. Apply sealant only where the manufacturer allows it, and keep the first thread or sealing face clear of debris. Tighten to the specified method for the connection type, because tapered threads, straight threads, gaskets, and O-rings seal in different ways.
Isolation valves and dedicated test points should be planned whenever the sensor may need safe removal, in-place calibration, or comparison against a reference instrument later. A block-and-bleed arrangement can reduce unnecessary process shutdowns and allows pressure to be relieved before removal. The layout should still avoid dead legs, trapped fluid, and extra fittings that add leak points or make the reading sluggish.
Strong vibration and rapid pressure pulsation can shorten sensor life and make the output look unstable, so mechanical damping must be considered before commissioning begins. Damping may come from a snubber, restrictor, pulsation dampener, flexible mounting, or moving the transmitter away from the vibrating source. Match the damping approach to the process, because too much damping can hide real pressure changes needed for control or protection.
Outdoor, washdown, and dusty installations require enclosure, cable-entry, and connector protection that matches the actual exposure, not only the nominal pressure-measurement requirement of the loop. Check the manufacturer’s ingress-protection and temperature ratings for the installed orientation, connector style, and cable gland. Use drip loops and strain relief where appropriate, and avoid mounting positions that let water sit against seals or electrical entries.
Very low-pressure measurements are especially sensitive to mounting position, trapped air, tubing volume, drafts, and small leaks, so installation details can dominate the stated sensor accuracy. Use short, leak-tight connections, minimize unsupported tubing, and avoid placing sensitive devices where airflow or temperature gradients disturb the reference side. After installation, compare the reading at known zero and at an operating point if the process allows.