The residual quantity sensors are used for level measurement in potentially explosive atmospheres. Both the level detector and the measuring transducer are integrated in a stainless steel housing. A prism is located at the lower end of the level sensor.
How it works
An electrical signal in the measuring transducer triggers a light pulse by means of an infrared LED. In the dry state (when the prism is not immersed in liquid), the light is reflected in the prism and directed back onto a photodiode. The photodiode converts the light pulse into an electrical signal that is output as a return signal.
However, if the prism is wetted by liquid, there is no reflection onto the photodiode. The light beam is deflected by the altered refractive index in the medium and the return signal is absent, which means that there is no release.
Performance features
Areas of application