Tuesday, August 11, 2009

How to Diagnose a Broken Optical Sensors

If you are using optical sensors you might aware of few problems such as:
  • broken fiber optic which causes weak light beam
  • dust covering the optic head
  • decrease in reliability over time
  • too sensitive to changes of environment or detecting target
  • and many more of course
We will focus on these few right now. Lets talk about the first issue

Broken fiber optic
Over the past few years, people have been telling me that they have problem with their sensors such as "broken light beam sensor" or purely "my optical sensor is broken". If you get to know more about the sensor, then you will know that this are not the things to say. Specifically, when an optical sensor is not functioning well, it has to be either the amplifier/controller or the optical head which is the fiber thing attached to the main unit/controller.

So what you have to do when the sensor is going haywire is just a very simple diagnostic.

Check the amplifier. If it is a digital type of amplifier, monitor the numbers which indicates the intensity of light received by the receiver. Check it with and without the presence of the detecting object. Is there a huge difference or just a very subtle difference? If the difference is huge but there is no output generated through the output wire, then yes, it should be wiring problem or output is broken. In this case, the whole main unit has to be replaced. The optical head which is attached to the main unit can be reuse. You are sure of that because the difference between the figure for the absence and presence of object is huge.

If the difference is very little or insignificant : -
1. Check the optical sensors head for dust or particle. Clean it.
2. If there it is clean and still giving the same results, check the detecting distance of the sensor head. Each sensor head comes with different detecting distance. Make sure it is installes in the correct range of distance.
3. If it is still not working, check the amplifier. Usually it comes with a feature to increase the light intensity.
4. If sensor head is in good position and clean, but still not working well, check for broken fiber internally.
Unplug the head from the main unit. Put an object right in front of the amplifier where it emits llight. Monitor the numbers on the main unit. If there is a huge difference when there is and object in front, then it is confirmed that you have a broken optical sensor head.

Good luck in checking for broken fiber optical sensors.