The 6 Fast-And-Dirty Guide to Troubleshooting Photoelectric Sensors

A photoelectric sensor is a device that traces a difference in the light level received from the source of light. The sensor itself is made up of a light source, an amplifier, a signal converter, and an output. There are generally three types of photoelectric sensors: thru-beam, retroreflective, and diffused of which have their own strengths and can be used in a variety of ways. Having said that, when you have a photoelectric sensor of some type that not working. What's the fastest way to fix it? Identify the Sensor Type As mentioned before there are three basic kinds of photoelectric sensors and you have to know what type you have:

a. Through-beam sensors have an emitter and a receiver, and trigger whenever the beam between the two is broken in. They offer the longest operational range. Having said so, along with its lengthy life, expect that you will be encountering malfunctioning episodes. These are the steps that might be helpful: Due to the vibration or shock, the optical axis may have been modified. Do the following procedure to adjust the optical axis if sensors have a sensitivity adjuster. Place the sensitivity adjuster halfway between MIN and MAX. Change the optical axes of the emitter and receiver at that sensitivity. Move the emitter up and down and to the left and right to adjust it to the center of the angle range for receiving light. Advance the receiver up and down and to the left and right to change it to the center of the angle range for receiving light. Finally, place the sensitivity adjuster to MAX.

b. Retro-reflective sensors have an emitter and receiver in a single unit and need a reflector to be put in such a way that the beam is bounced back into the unit. They're the most common type of photoelectric sensor.

c. Diffuse sensors depend on the small percentage of light that reflects back into the sensor from a nearby object to trigger; they have the shortest detection range of all but are also the cheapest and the most convenient to install. Identify the Problem Is the sensor going off when there's nothing to sense, or is it not going off when there is something to detect? It is possible to check if the tester is used. It is checked in the following method whether the control output operates normally with a tester. Clean the Apparatus This is basically when the troubleshooting starts. If it's the first case, and the sensor is registering false positives, then begin by cleaning the entire sensor: which means cleaning the beam output, the receiver, and if present, the reflector. Simply use a soft clean dry cloth and, if the sensor is visibly dirty, a non-abrasive, non-corrosive cleanser is the best tools. Test the sensor to see if it works after cleaning the sensor parts thoroughly. Re-align the Parts If for some reason, after steps 1 to 3 they're still not working, carefully re-align the entire system. This requires a string and two people (exception: a diffuse scanner works at such a small range so it should visually obvious of its misalignment.) Assign one person to stand at one end of the arrangement and another stand at the reflector/receiver, and pull a string taut between the two. If the photo eyes are misaligned, line them up using the string, starting in the left-right dimension and then in the up-down dimension. Proceed to make minor adjustments to the emitter only until the sensor is functioning properly once they are roughly aligned. Check the Inputs One of the basic pieces of information you need to know is that the inputs for a photoelectric detector are electrical. Examine the sensors' data sheets and make sure that they are receiving the right voltage, amperage, and AC or DC current. Using a multimeter or other measuring tool is required to ensure that the right amounts are making it all the way through the circuit to the emitter and receiver. Contact the Dealer. And finally, if all else fails, after processing steps 1 to 5, contact the dealer who sold you the sensors - they can discuss with you other more multiplex procedures that you can venture including changing the gain adjustment and tapering the beam.