Electro-sensitive protective device
A non-contact protective device (ESPE) is a protective device that detects the intrusion of a body part into a protective field with the help of sensors that work without direct mechanical contact.
It can be based on various physical principles:
- optical ( light curtain , laser scanning , infrared motion detector , digital cameras together with pattern recognition or image comparison)
- acoustic (via ultrasound )
- inductive ( inductive proximity switch , only for electrically conductive objects)
- capacitive ( capacitive distance sensor , only for distances that are small compared to the sensor diameter)
Protective devices that do not aim to detect a part of the body are not referred to as ESPE (e.g. non-contact safety switches, sensors for detecting radiation and fields).
Electro-sensitive protective devices comprise the following elements:
- a sensor function
- a control / monitoring function in an evaluation device such as B. safety controller, safety module, safety switching device or evaluation unit
- Output switching elements OSSD (Output Switching Signal Device) that go into the OFF state when the control or monitoring function responds.
General requirements and tests of ESPE are described in EN 61496 Part 1 to Part 4 .
The required safety distances between the ESPE and the dangerous movements that it protects against are determined in accordance with the EN ISO 13855 standard (previously EN 999).