Glossary · Sensors and measurement
Pressure sensor
Also known as: Pressure transducer, Pressure transmitter
German: Drucksensor
In measurement technology, a pressure sensor is a sensor that measures the pressure of a gas or liquid, as gauge, absolute or differential pressure, and converts it into an electrical signal, commonly with piezoresistive, capacitive or thin-film strain-gauge elements.
- Sensors
In one sentence
A pressure sensor measures gauge, absolute or differential pressure of gases or liquids and converts it into an electrical signal.
Example
A pressure sensor in the hydraulic unit of an injection molding machine reports the system pressure to the controller for closed-loop control.
How it applies
- Engineering: Specify the pressure type (gauge, absolute, differential), measuring range, overload limit, media compatibility and process connection. Pressure peaks from valves or pumps can exceed the overload limit and damage the sensor.
- Installation: Damping elements, siphons for steam or diaphragm seals for aggressive or hot media are part of the measuring point.
- Maintenance: Before removing a pressure sensor, the line must be depressurized. Residual pressure is a hazard, so the procedure belongs in the maintenance manual.
- Documentation: State the pressure type with every value (bar g, bar a). Unqualified bar values cause errors in commissioning and in interfaces.
Pressure sensor vs. pressure transmitter
A pressure sensor can be a bare sensing element or a complete device. A pressure transmitter includes electronics that deliver a standardized output such as 4–20 mA and often configuration and diagnostics.