How to Select a Pressure Sensor: A Five-Step Guide to Type, Range and Output

Check five areas when selecting a pressure sensor: reference, range, output, connections and ingress protection, then accuracy and temperature. Start with the process medium and operating conditions and use the selected revision’s specifications. This checklist does not replace compatibility, transient, complete-device or project validation.

Three operating conditions to settle first

Condition	What to establish	Why it matters
Media	Gas or liquid, corrosive, particle content, temperature	Check wetted metal, seals, concentration and temperature; specifying 316L alone does not establish medium compatibility
Pressure range	Normal working pressure, possible transient spikes, any vacuum phase	Distinguish measuring range from withstand limits; validate repeated pulses
Temperature and shock	Media and ambient temperature, water hammer or high-frequency pulsation	Determines compensated temperature range and whether a pressure snubber is needed

Step 1: Choose the pressure type

Pressure type defines the reference: local atmosphere for gauge, vacuum for absolute, and a sealed reference for sealed gauge. A mismatch can introduce a reference error. A single zero adjustment may not correct changes with atmospheric pressure, especially at low pressures or high altitude.

Type	Reference	Typical use
Gauge (relative)	Current ambient pressure	Open tank level, ventilation ducts, most hydraulic and pneumatic systems
Sealed gauge	Standard pressure sealed in at manufacture	High-pressure systems, outdoor installations where a vent must be avoided
Absolute	Vacuum	Barometric pressure, sealed vessels, altitude-related measurement

Choose pressure type by the required reference, not to obtain IP68. PM160-E distinguishes gauge IP67 from absolute/sealed-gauge IP68, subject to connector and assembly conditions. Where true gauge measurement and possible immersion are both required, confirm a suitable vent and installation-protection arrangement.

Step 2: Set the range

Normal pressure at roughly one-third to two-thirds of full scale is a starting heuristic, not a universal rule. Cover the highest pressure that must be measured while checking absolute error and resolution. Separately assess overload, repeated pulses and snubbing; burst pressure is not an operating limit.

For an illustrative 6 bar operating pressure and 20 bar abnormal peak, WA30’s 0–10 bar version lists 50 bar overload and 300 bar burst. A 20 bar peak exceeds its measuring range and cannot be recorded accurately on that range. Select a range covering 20 bar if peak measurement is required; validate withstand and measuring range separately.

Step 3: Choose the output signal

Output	Practical distance	Supply	Best for
4-20 mA current	Suitable for long runs subject to total-load calculation	Model-specific (PM160-E example 9–32 VDC)	Industrial plants, PLC inputs, noisy environments
0.5-4.5 V ratiometric	Short	5.0 +/- 5% VDC	Vehicle systems, battery power, direct MCU sampling
0-10 V / 1-10 V	Short to medium	21–30 VDC	In-cabinet machine control
I2C / SPI digital	Board level	3.0-5.5 VDC	Embedded and IoT nodes, when temperature is also needed
Modbus 485	Long, multi-drop	Model dependent	Networked installations, SCADA
NB-IoT / 4G	Limited by network coverage and site conditions	Battery or external	Pipe networks, remote sites, no cabling

A short rule of thumb: current for distance, voltage for short runs, digital when you need temperature or low power, wireless when you cannot cable. If pressure and temperature are both required, the RS PM160-DV dual-output sensor delivers both over I2C/SPI; for classic industrial transmission choose the RS PM160-E analog transmitter.

Step 4: Process connection and ingress protection

The process connection must match the existing piping: common options are G1/4 A face sealing, G1/4 A O-ring, 1/4-18 NPT, 7/16-20 UNF and M12x1.5. Electrical connections typically use M12x1 (EN60947-5-2), Metri-Pack, or Hirschmann Type A (EN175301-803-A). These two groups are the most frequently mismatched items when different people specify them.

State the complete configuration and exposure conditions. For possible flooding, confirm depth, duration, connector, venting and installation. Rain and prolonged immersion are different duties; IP68 is not a universal requirement for every outdoor point.

Step 5: Accuracy over temperature — TEB is not the same as accuracy

Check the definitions of room-temperature accuracy and TEB separately. Included error terms depend on the model specification. Read TEB with its temperature band, typical or maximum basis, pressure range and configuration; figures with different conditions cannot be ranked directly.

Model	TEB basis	Conditions	Mechanical limits
PM160-E	Typical ≤±0.25 % FS; maximum ≤±0.50 % FS	−20 to 85 °C; check the specified TEB profile for other bands	Range-specific
PM400-E	Confirm selected range and revision	Confirm temperature band and typical/maximum basis together	2–5×, range dependent
PM160-DV	≥1 bar: typical ±0.25 % FS; maximum ±0.50 % FS	-20 to 85 °C; ≤2 bar also confirm footnote and order	Range-specific
WA30	≤±0.50 % FS (not relabelled as typical)	-20 to 85 °C, altitude 0–100 m	Range-specific; not a dynamic water-hammer guarantee

Compare TEB on a consistent basis. PM160-E lists typical and maximum values by temperature band; PM160-DV also separates pressure ranges; WA30’s ≤±0.50 % FS applies at -20 to 85 °C and 0–100 m altitude. Do not label every model’s figure as “typical” and rank them directly.

Seven common selection mistakes

Mistake	Consequence	What to do instead
Using room-temperature accuracy as a full-range figure	Out-of-spec readings in winter or summer	Request TEB typical and maximum for the actual operating range
Sizing the range tight to working pressure	Spikes damage the diaphragm	Cover measurement peaks; separately assess overload and repeated pulses
Ignoring transient spikes	Diaphragm fatigue, zero drift	Assess dynamic pressure, snubbing and response requirements
Mixing gauge and absolute references	Reference error, potentially changing with atmospheric pressure	Confirm the reference before ordering
Not accounting for cable length	Voltage output sags at the far end	Check signal, total load, cabling and host input
Assuming one IP rating covers the whole series	Gauge version falls short of IP68	Confirm per pressure type
Media incompatible with wetted materials	Corrosion and leakage	Check SUS316L and seal material compatibility

Rodee product line at a glance

Level	Series	Range	Output	Typical use
Uncompensated low-pressure core	RS PC070	0–5 / 15 / 30 psi; 1 psi custom	mV	Low-pressure OEM integration
Uncompensated medium-pressure core	RS PC160	0–5 / 10 / 30 / 40 bar; 160 bar absolute only	mV, by range and excitation	OEM integration, transmitter development
Uncompensated high-pressure core	RS PC350	0–100 / 160 / 250 / 350 bar (absolute)	mV, by range and excitation	High-pressure pumps, hydraulics
Calibrated core	RS PMSC350	Confirm selected pressure range and version	0.5-4.5 V, I2C	When a ready-to-use signal is required
Analog transmitter	RS PM160-E	0–0.1 to 160 bar	4–20 mA / voltage, by version	General industrial duty
Digital dual output	RS PM160-DV	Low, negative and standard ranges; confirm version	I2C / SPI	IoT, pressure plus temperature
Outdoor display	RS WA30	0-10 / 20 / 30 bar (custom on request)	4–20 mA / voltage / RS485; I²C on request	Fire mains, water supply, submersible equipment
Wireless terminal	RS PM350-RTU	0-1 to 350 bar	NB-IoT / 4G	Remote pipe network monitoring
Level transmitter	RS PMLG150	Confirm against project and actual product documentation	Confirm selected version	Level measurement

Next step: check every item against the datasheet

Once the selection is settled, turn the five dimensions above into a checklist and tick each one against the datasheet. Full parameter tables for every series are available on the downloads page. Where duty involves high-pressure pulsation, aggressive media or a non-standard range, contacting Rodee’s technical team directly is usually faster than iterating on your own.

More answers in the FAQ.

Specifications: View MEMS PC070-P Datasheet (PDF) · Download PDF · View PM160-E Datasheet (PDF) · Download PDF · View PM160-DV datasheet (PDF) · Download PDF