The optical level switch has been designed for use in level monitoring applications for the control of the liquid presence/absence and can be suitable for a lot of applications. The switch has no moving parts, thus it is particularly suited for monitoring media where high reliability is needed.
For minimum / maximum level detection the switch must be mounted at the desired height and gives an alarm when low (or high) liquid level is detected.
The sensors contains an infrared-ray emitter and an optical receiver. In air (liquid not present), all the light emitted is reflected - internally - by the dome and then redirected to the receiver. When the liquid reaches the sensor dome, a big amount of the light emitted is lost in the liquid and the sensor senses its presence.