How to choose the right pressure sensor for industry

Which measuring range and pressure type do I need?

The measuring range must match the process: as a rule of thumb the maximum operating pressure should sit at about 60 to 70 % of the nominal range so that peaks do not reach the overload limit. Equally important is the pressure type, the reference point of the measurement.

Gauge pressure measures against ambient air pressure and suits hydraulics, pneumatics and most process pressures. Absolute pressure references a vacuum and is used for weather or packaging applications. Differential pressure captures the difference between two points, for example across a filter.

Which output signal fits your controller?

The output signal must match the PLC or controller. The analog current output 4‑20 mA is the industry standard because it is immune to line resistance and long cable runs, and a wire break is detected immediately at the 0 mA level.

• 4‑20 mA (2-wire): noise-immune over long distances, wire-break detection included.
• 0‑10 V: simple wiring, but sensitive to voltage drop on long cables.
• IO-Link: digital point-to-point communication with diagnostics, parameterisation and remote configuration.
• Switching output PNP/NPN: for simple limit monitoring without a continuous reading.

How do I ensure media compatibility?

The measured medium determines the material and design of the wetted parts. For aggressive, corrosive or ultra-pure media, stainless steel 1.4404 (316L) or ceramic sensing cells are the first choice, while standard hydraulic oils are compatible with more economical alloys.

For viscous, crystallising or fibrous media a flush-mounted diaphragm is recommended so that no residue collects in a pressure channel bore. In food and pharma applications, hygienic process connections such as clamp or flush G1/2 plus EHEDG or 3-A conformity are required.

How much accuracy and which ingress protection?

Accuracy is usually given as a percentage of full scale (% FS) and combines linearity, hysteresis and repeatability. Standard control loops often manage with 0.5 to 1 % FS, while precise test benches demand 0.25 % FS or better.

• Total error band: realistically combines non-linearity, hysteresis and temperature drift.
• Temperature compensation: important when medium or ambient conditions vary widely.
• Ingress protection IP67 or IP69K: for humidity, splash water and high-pressure cleaning.
• EMC immunity per EN 61326 keeps readings stable in electrically noisy environments.

Frequently asked questions