Difficult targets and unique application requirements call for specialized sensing technology. When over-the-counter medication producers and packaged food manufacturers were faced with the challenge of coming up with a response to concerns about protecting consumers from potential tampering, they turned to modern luminescence sensor technology.
A luminescence (or UV) sensor functions similar to standard photoelectric sensors. Their main difference is that they use an ultraviolet LED emitter (typically 370nm in wavelength) which, after striking the target, is transformed into a visible light by the natural luminescent properties of the target. The amount of the returned light is monitored and used for turning on the sensor’s discrete output or is transformed to a proportional analog output.
Many objects respond well to ultraviolet light. For example, most types of grease shine brightly when struck with a UV light. Other types of targets often detected with luminescent sensors are glue, colored paper, and labels. In cases where more luminescence is needed, dyes can be added to materials, or targets can be marked with specially designed grease pens.
Whether it’s lumber sorting, glue detection, or safety seal verification, luminescent sensors are designed to help you see targets that other conventional types of sensors may not.