The optoCONTROL CLS-K fiber optic sensors consist of a transmitter and receiver for infrared or ultraviolet light with subsequent signal processing. Measurement is made directly on the object using fiber optics. The selection of the electronic amplifier is the key to successfully solving this measurement task. The correct fiber optic is then selected depending on the measurement task at hand. The decisive factors are the distance from the object to the electronics, as well as the minimum installation space required.