Looking Into & Through Transparent Material With Photoelectric Sensors

Advance automated manufacturing relies on sensor equipment to ensure each step of the process is done correctly, reliably, and effectively. For many standard applications, inductive, capacitive, or basic photoelectric sensors can do a fine job of monitoring and maintaining the automated manufacturing process. However, when transparent materials are the target, you need a different type of sensor, and maybe even need to think differently about how you will use it.

What are transparent materials?

When I think of transparent materials, water, glass, plexiglass, polymers, soaps, cooling agents, and packaging all come to mind. Because transparent material absorbs very little of the emitted red LED light, standard photoelectric sensors struggle on this type of application. If light can make its way back to the receiver, how can you tell if the beam was broken or not? By measuring the amount of light returned, instead of just if it is there or not, we can detect a transparent material and learn how transparent it is.

Imagine being able to determine proper mixes or thicknesses of liquid based on a transparency scale associated to a value of returned light. Another application that I believe a transparent material photoelectric senor would be ideal for is the thickness of a clear bottle. Imagine the wall thickness being crucial to the integrity of the bottle. Again, we would measure the amount of light allowed back to the receiver instead of an expensive measurement laser or even worse, a time-draining manual caliper.

Transparent material sensor vs. standard photoelectric sensor

So how does a transparent material sensor differ from a standard photoelectric sensor? Usually, the type of light is key. UV light is absorbed much greater than other wavelengths, like red or blue LEDs you find in standard photoelectric sensors. To add another level, you polarize that UV light to better control the light back into the receiver. Polarized UV light with a polarized reflector is the best combination. This can be done on a large or micro scale based on the sensor head size and build.

Uses for transparent material sensor include packaging trays, level tubes, medical tests, adhesive extrusion, and bottle fill levels, just to name a few. Transparent materials are everywhere, and the technology has matured. Make sure you are looking into specialized sensor technologies and working through best set-up practices to ensure reliable detection of transparent materials.

A Simple Way to Improve Speed and Efficiency

We are all efficiency-hungry. We want everything from service in restaurants to production on our plant done efficiently. Sometimes we use the term “speed” interchangeably with efficiency. Is that really a big deal? Of course it is.  How many times have you placed an order at the drive-through window of a fast-food chain and gotten wrong items or incomplete orders? Why do they make mistakes? Because, they are measured on customer response time (speed) and not on accuracy of the delivery (efficiency) — again speed replaced efficiency.

So is the maintenance team at your production plant efficient or speedy?  In my opinion, once you have the right maintenance person for the problem at hand they would be both efficient and speedy. The point I want to make is that identifying what type of maintenance service your system needs is the important part in making your maintenance team efficient in responding. Another way would be hiring all-rounder maintenance person who can handle electrical, mechanical and all other issues that your system can throw at him/her. How many of those all-rounders you can find and keep?

Today, in most plants we see three-segment or five-segment stack lights on almost all sorts of equipment that tells you the status of the work-cell: Green = everything good; Red = Need maintenance now!!! But, does it tell you about type of maintenance? So, what do we do? We send our maintenance tech out to the system; he looks up error codes on the small 8×10 HMI and figures out that the system needs an electrical tech to handle the situation. Wouldn’t it be nice, if that stack-light was a little smarter to tell you that “Hey, this system needs {electrical, pneumatic or mechanical} maintenance” instead of just flashing a red light? If it was that intelligent it would probably also tell you that this work-cell is running out of raw materials, or how the system is performing to the production quota etc.

SmartLightWell, I have great news: since the introduction of our one of a kind SmartLights our customers shared so many novel uses of this intelligent LED tower light that it is hard to capture all of them in one blog. I would like to share some quick examples though. As this SmartLight has three programmable modes of operations; stack-light mode, run-light mode and level mode, there are several possibilities of showing different information about the system using the single SmartLight. In one application, when the system needs operator/maintenance intervention, the controller (PLC or computer) switches the SmartLight in run-light mode and utilizes different combinations of foreground and background colors to indicate what type of maintenance and what severity of maintenance is needed. In another application, our customer utilizes the level mode of operation to show how different stations are performing so that plant supervisor and pin-point the bottleneck of the process and provide needed support to ensure efficient operations in the plant. Furthermore, lots of these applications were done as an after-thought to the existing systems in place.

SmartLight is one of the ways to improve your efficiency and speed. If you have unique SmartLight application to share feel free to comment on this blog.

Learn more about the SmartLight in our video library or on our website at www.balluff.us/smartlight.