Video Transcript:

Mike:

What's up Industrial Automation world. I'm Mike. I'm the Marketing Manager for Scott Equipment Company. Today, we're excited. We've got Steve Jerome from DataSensing here. And today he's going to talk about sensors, and how they work and where you can use them in your application. Steve, take it away.

 

Steve:

Thanks, Mike.

 

Today we're going to talk a little bit about different sensing modes for photo eyes. Here on this board, we've got a through beam, retro reflective, diffuse sensor, fixed focus, and background suppression. These are all different sensing modes.

 

I'm going to start with a through beam, the through beam is an emitter and receiver, it's actually two pairs, the emitter sends the light to the receiver, the receiver looks for the light. And when something gets in the way, we get an output. So the most reliable way to sense is through a beam. As long as it's not a clear object. It'll sense whatever is coming through it, be it a sensor, be it a piece of cardboard, be it my finger, it doesn't care, color won't matter either.

 

The next sensing mode, which is your second most reliable sensing mode is retro reflective. It's kind of like a, you've got the emitter and receiver built into one sensor head. So here we're taking the light, we're sending it up to a reflector, it bounces off of the reflector and comes back to the sensor. And again is looking for something to block the light path. So when I put an object in front of it, it will go ahead and sense that object. The only thing that sometimes can fool a retro reflective sensor is a very shiny or mirror like surface that simulates the reflector a little bit too closely. Sometimes that can fool retro reflective sensor where we won't see a real shiny object.

 

The next sensing mode is diffuse, diffuse has the emitter and receiver built into the sensor head as the same as the retro reflective does. But instead of going for a reflector and looking for something to block the light, the diffuse, gets the light bounces off the object and comes back to the sensor. Now the diffuse is a little bit more susceptible to things like color. Here I'm using a white business card and I can get it quite a ways away and still see that card. If I go ahead and take something like this brown cardboard, I can't get nearly as far away. Or if I happen to have a dull black surface, like the side of the sensor, I actually have to get rather close before I will actually sense it. That's one of the downfalls of diffuse, it is color sensitive, shiny surface versus a dull matte surface will affect the sensor differently. You'll see a shiny surface further away than you'll see a dull dark surface. Sometimes that can trick the sensor where you're trying to sense an object close. But somebody like someone with a white shirt happens to come by walking beyond the target and they set the sensor off with their white shirt. Those are some things you have to look out for with diffuse.

 

Another mode of sensing is our fixed focus. This one in particular has a 70 millimeter range. So it tends to sit right at a certain edge. And it pretty much stays right on that edge, it does get affected a little bit by color, I can go ahead and take this dark, this cardboard, I do have to get a little bit closer to sense, but it is right on that edge again. So this is a great sensor for having particular cut off range or something of that nature where I'm only going to go on about so far. And that's what I'm going to see where this I've got to can move a lot and not affect the sensor here. Little bit of movement makes a big difference on something like a fixed focus sensor.

 

And the last sensing mode I'm going to talk about is background suppression. Background suppression like the fixed focus has a tight cut off, but it's even tighter than in many cases. Here I've got a block, there's three settings for this block. Right now I've got it set at the middle. If I come closer to the sensor, I'm okay. But if I go back, there's the middle. If I go to the far mode, I don't see that even though it's the same target. There's a tight cut off on the background suppression. We taught the sensor at this point. And we ignored the background beyond that point where you're suppressing the background, what's behind the top point on the sensor. So therefore, I move it just a little bit of a quarter to a half an inch. And we can no longer see the target because it's now in the background and what we taught though.

 

So those are your different sensing modes for photoelectric sensors. If you have any questions about anything, contact your Scott Equipment Company rep. And we'll be happy to come out and give you a demo. Have a great day.

 

Mike

Steve, appreciate your time. My pleasure came up today and you gave us a great explanation on the different sensing modes on how each sensor works and why they're different. So we appreciate you visiting us today and giving us the best explanation I've seen on how these sensors work. If you have any questions, reach out to your local Scott Equipment Company Account Manager. If they don't have an answer. They're calling this guy,

 

Steve:

and I'll be happy to come up and help you with your application.

 

Mike:

Awesome. So we've got plenty of resources to make sure you get the right sensors for your application. Thanks for taking some time to watch today's video. Be sure to subscribe to our YouTube channel for more great industrial automation videos. Thanks, Steve.

 

Steve:

Thank you. Bye. Have a great day. Thanks