Self-compensation inhibits pre-attenuation of non-flush mountable sensors and enables partial embedding of the same with reduced switching distance.
If strong reflecting objects have to be detected with retroreflective sensors a polarizing filter is required. A triple reflector redirects the light beam by 90°, maintaining the polarization of the light reflected by the object‘s surface. The polarizing filter enables the sensor to distinguish between light thrown back from the object or from the reflector.
Photoelectric sensors operate on the principle of emitting and receiving light. All sensors in this catalog are compact devices having optics, amplifier and switching output in the same housing. A diode emits a light beam which is either cut off (opposed mode) or reflected by an object (retroreflective/diffuse mode). The sensor detects a change in light intensity causing the output to switch. Photoelectric sensors operate with modulated light in order to blank out unwanted influence of ambient light.
Plastic fibre-optics are single strands of fibre- optic material, typically 0,25 to 1,5 mm in diameter. Most plastic fibre-optics are terminated at the sensing end with a bendable probe or threaded tip. The other end is not terminated, therefore it can be cut to length on site with the special cutter supplied. Unlike glass fibre-optics, plastic fibres will tolerate repeated flexing. In fact, pre-coiled plastic fibre-optics are available for sensing applications on reciprocating mechanisms.Plastic fibre-optics require a visible light source for effective sensing as they absorb most infrared wavelengths. They are also less tolerant of temperature extremes and are sensitive to many chemicals and solvents.Individual plastic fibre-optics (for opposed mode sensing) are sold as pairs.