The IFM PN3571 is a compact electronic pressure sensor with an integrated digital display, designed for precise monitoring and control of medium to high pressures in industrial automation. It combines a robust metallic thin-film measuring cell, a programmable switching output, a fully scalable analogue output (4–20 mA / 0–10 V) and IO-Link communication in one device.
1. Core Technical Data (Quick Reference Table)
| Item |
Description |
| Manufacturer / Series |
IFM– PN series pressure sensors |
| Model designation |
PN3571 / PN-250-SEG14-MFRKG/US/ /V |
| Measuring range |
0…250 bar, 0…3620 psi, 0…25 MPa |
| Type of pressure |
Relative pressure, vacuum resistant to -1000 mbar |
| Measuring element |
Metallic thin-film pressure cell |
| Media |
Liquids and gases in industrial applications |
| Pressure rating |
500 bar (50 MPa) |
| Minimum bursting pressure |
1200 bar (120 MPa) |
| Process connection |
G 1/4 external thread, internal M5, sealing FKM |
| Outputs |
1 digital switching output + 1 analogue output, IO-Link configurable |
| Analogue output |
4–20 mA (max 500 Ω) and 0–10 V (min 2 kΩ), selectable |
| Output current rating |
150 mA (up to 200 mA at 60 °C, 250 mA at 40 °C) |
| Supply voltage |
18…30 V DC, SELV/PELV, DC PNP design |
| Accuracy (switch point) |
< ±0.5 % of span; repeatability < ±0.1 % |
| Medium / ambient temperature |
–25…80 °C |
| Protection rating |
IP65 / IP67 |
| Display |
4-digit red/green alphanumeric display, LEDs for units and switching |
| Electrical connection |
M12 connector, gold-plated contacts |
2. Measuring Range and Metrological Performance
With a measuring range from 0 to 250 bar, the PN3571 is aimed at applications where standard hydraulic and high-pressure coolant circuits need both reliable switching and stable analogue feedback. It covers typical system pressures in hydraulic power packs, clamping systems and booster pump skids without being oversized.
The datasheet specifies a switch point accuracy better than ±0.5 % of span, characteristic deviation under ±0.25 % (BFSL) and repeatability below ±0.1 %, with long-term drift typically less than ±0.05 % over six months. These values mean that once the set and reset points are adjusted, the PN3571 will maintain consistent trip levels, even as temperature fluctuates within the –25…80 °C range. Temperature coefficients of only 0.2 % of span per 10 K for both zero and span further support stable measurement over time.
This combination of accuracy, repeatability and stability allows the sensor to serve not only as a limit switch, but also as a trustworthy process value source for trend monitoring and basic closed-loop control.
3. Mechanical Construction and Process Interface
Mechanically, the PN3571 is built around a metallic thin-film measuring cell mounted behind a stainless-steel diaphragm. This technology offers high overload resistance, excellent fatigue strength and good compatibility with common hydraulic and cooling media.
The process connection is a G 1/4 external thread with an internal M5 port and an FKM sealing ring, complying with DIN EN ISO 1179-2 and DIN 3869. This makes it easy to integrate into manifolds, blocks and pipe fittings that follow European or international standards. A pressure rating of 500 bar and a minimum bursting pressure of 1200 bar provide a generous safety margin, making the device resilient against short-term pressure spikes in dynamic hydraulic circuits.
Housing materials include stainless steel 1.4542 / 316L and reinforced plastics such as PBT+PC-GF30, with IP65/IP67 protection and vibration/shock resistance up to 20 g and 50 g respectively. The upper housing can be rotated by about 345°, letting you align the display and buttons optimally after tightening the sensor into the process port.
4. Outputs, Analogue Function and IO-Link
A key strength of the PN3571 is its multi-signal output concept. The device provides two outputs in total:
The switching output is PNP, with programmable normally open or normally closed behaviour, and can switch up to 150 mA continuously, rising to 200 mA at 60 °C and 250 mA at 40 °C. Short-circuit and overload protection are integrated.
The analogue channel provides a 4–20 mA output with a maximum load of 500 Ω and a 0–10 V output requiring at least 2 kΩ load resistance. Response times are fast: both switching and analogue outputs can react in under 3 ms, and programmable delays and damping (0…50 s and 0…4 s respectively) help filter out brief transients so that controllers see a clean signal.
When IO-Link is enabled, the PN3571 behaves as a smart device supporting COM2 transmission, IO-Link revision 1.1 and the IEC 61131-9 SDCI standard. It can send one analogue process value plus binary status information with a minimum process cycle time of 2.3 ms.
5. Display, Local Operation and Diagnostics
On the front, the PN3571 offers a 4-digit alphanumeric display that can show the measured pressure in bar, psi or MPa. The display can alternate between red and green, giving a clear visual indication of normal operation versus alarm states.
Three green LEDs indicate the active unit, while a yellow LED shows the switching status. Three pushbuttons under the display give access to a structured parameter menu. The configuration options include hysteresis or window mode, NO/NC logic, on- and off-delay, damping for switching and analogue outputs, display unit and choice of current or voltage on the analogue channel.
This combination of local display and keypad makes it easy to commission simple machines directly at the sensor. At the same time, IO-Link provides remote access to the same settings, enabling parameter cloning and centralised diagnostics in more advanced systems.
6. Typical Industrial Applications
Thanks to its 0…250 bar range, strong overload capability and compact design, the PN3571 fits a wide variety of pressure-related tasks, for example:
-
Monitoring main pressure in hydraulic power packs and power units.
-
Controlling clamping and tool clamping pressure on machine tools.
-
Supervising coolant and lubrication pressure in production machinery to prevent dry running and detect filter clogging.
-
Measuring pressure in booster pump systems and industrial washing or rinse processes that operate in the mid-pressure range.
-
Providing combined switch and analogue feedback in OEM skid packages and modular process equipment.
The sensor can be used with liquids and gases in PED fluid group 2, with group 1 fluids on request, as long as media compatibility and pressure limits are respected. High shock and vibration resistance, at least 100 million pressure cycles and an MTTF of around 165 years underline its suitability for continuous duty and frequent cycling applications.
7. Benefits for OEMs and Plant Operators
For machine builders, the PN3571 offers a flexible building block: one part number provides a 0…250 bar range, a digital switch output, a fully scalable analogue signal and IO-Link connectivity, all in a standard G 1/4 form factor with M12 plug. That simplifies electrical and mechanical design and reduces sensor variety across multiple machine models.
For end users and maintenance teams, the device delivers clear on-site indication, fast reactions, and strong protection features such as reverse polarity protection, pulsed short-circuit protection and overload protection. With IO-Link, engineers gain extra visibility into process values and sensor status, which supports condition-based maintenance and faster troubleshooting when a process deviates from its normal operating window.
In summary, the IFM PN3571 pressure sensor with display is a robust, versatile solution for 0…250 bar applications, combining high measurement performance, flexible signal outputs and modern communication in a compact industrial housing.
