Biotech level sensor

A smart way to avoid overfilling the waste bottle

The Biotech level sensor features a visual and acoustic alarm that is built-in to the level sensor. This signals with light and sound through a LED and a buzzer when the liquid reaches the glass rod and it can also send signals to other equipment via a TTL output. The level sensor is normally mounted on a GL45 bottle cap.

The level sensor consists of a ground glass rod, and electronics for detecting fluid on the rod end.  Light sent down into the glass rod is reflected back as long as the liquid surface level is below the glass rod. As soon as the liquid level reaches the glass rod the light is scattered away from the glass rod and the sensor detects this and gives an output. It is powered by 5 VDC and the output is a TTL. When the liquid level is below the glass rod the output is high (+5 VDC), and when the liquid reaches the glass rod the output is low (0 VDC).