Why You Need to Carry a Reflector

Photoelectric Sensor or Photo Eyes

They are all over almost every machine you will work on in an industrial setting. You will find hundreds to thousands of them on most types of material handling equipment. Think of your shipping sorters and conveyors.

They are pretty simple, sense light or the absence of light then do something. The line stops when the right one is blocked and starts back up when it sees light that bounces off a reflector. You see them bolted everywhere. Sometimes in spots you would not suspect, sometimes several feet away from the photo eye that is sending the signal.

The photo eyes themselves tend to be easier to see, with the wires sticking out and the color-changing lights. Because they are easier to spot, they are slightly less prone to accidental damage. Reflectors though, are constantly misaligned, missing completely or have only a small portion remaining from damage.

Of course! But so what? 

If you keep a reflector in your pocket, you can leave it in the troublespot temporarily, while you run back to the shop and grab the right one. 

If you just cleared a bad jam and the sorter is stuck in recirculation, you can force the incoming lane to move by putting the reflector in front of the full-line photo eye. Exercise discretion with this one, you don't want to make it worse. 

You can use it to simulate what would happen if you eliminated a certain photo eye altogether. You may end up finding a more efficient configuration by using it to bypass sensors you suspect have been too touchy for the operation. Later the PLC can be reprogrammed based on your findings.

Once you start keeping one in your pocket, you'll find more and more situations where it will come in handy. I tend to put reflective tape on my radio and ID badge. I sometimes forget a reflector, but I always have those two on me.

This might be your new favorite 'trick.'