Trying to find a replacement sensor

I am trying to rectify am issue on a machine, the sensors use reflectors and water spill on them all the time so very often the reflector or the sensor itself has water on it. The sensors are used for counting so at some point or the other when water is on the sensor I have to be standing around to watch the sensor and quickly wipe it off for it to count or use my finger to pass the sensor so that it counts and doesn't mess up the sequence of the operation.

What I wanted to know is if it's possible to replace the sensors with some that doesnt use reflectors and also they would have to be ip67 certified.

This is the model of the sensor I use (
SS6-0N-4E)

What is it that is actually being sensed ?

Hi,

You are writing how you clean the sensor, wich is not of interest to find a solution...
but you don't write how the sensor works, nor what it does (like Warpspeed wrote), nor about size, speed nor any other technical information....

How can we help?

Klaus

Better to try to figure out the cause of the water spill and reduce the same. I note that the sensor uses IR reflection but I do not know what it is actually counting.

This is becoming far too common.

A post like:

My machine does not work, it sometimes rejects the blue ones.
But on Tuesdays it only displays 1,500

How can I fix it ?

Is it asking too much to give some minimal information about the sensor type and how it's mounted on your machine.

Found that SS6-0N-4E is an industry standard reflective photoelectric sensor ("light barrier").

I see these options:
- use a through-beam sensor pair instead
- design cover plates to prevent water spilling on the sensor
- move the sensor/reflector outside the wet zone

Place a clear glass angled on top of the sensor. Falling water will drift down and the IR beam is not affected as the cover on top is clear glass.

It's a photo electric sensor, anything that passes between it and the reflector it will sense it. It's connected to a plc which does the counting, in my case it counts bottles. The sensors are placed in fixed locations to determine where first and last bottles are located so I cant move them, I would just need another type of sensor which is water proof, use 0 to 30v and doesnt use a reflector.

Hi,

so is the sensor the problem or the reflector? Which one you have to wipe clean?

Is it clean, pure water or is there any cleaning agent or dirt in the water?

What causes the problems? is it caused by big water drops spilling around, or is it more like fog?

What length of clear distance do you have between the sensor and the bottles?

Is compressed air available in your system?

Klaus

You can use a interruptive sensor that uses a light beam (like one in the old mouse) interruption but that means you need to put the source and detector at opposite sides. That may increase complexity. But how that will solve your problem? (anyway, I do not understand what is the real problem)

The closest that comes to mind is an ultrasonic sensor. It is water proof, rugged and reliable. Have a look at this - https://www.pepperl-fuchs.com/global/en/24176.htm. There could be other manufacturers.

I don't believe that an ultrasonic sensor is per se better suited for counting bottles than an optical ones. Both are waterproof by design, both will be affected by large water drops on the sensor surface. But ultrasonic is surely another option.

But don't you think that some arrangement that prevents water to come to the sensor will be better? Are you looking for something more than that?

But don't you think that some arrangement that prevents water to come to the sensor will be better?

Click to expand...

It's indeed hard to believe that "water spill on them all the time" is considered normal operation. But we don't know much about the situation. Either the machine is operated under different conditions than expected by the manufacturer, or it's badly designed.

On the other hand, seeing sensors polluted, blinded, damaged or somehow "not working" is just everyday business of maintenance engineers in industrial automation. There are many reasons and many possible solutions. I think some good suggestions have been made, it's the OP's job to find what's applicable.

It's just a case of bad design, sensors are water proof so they don't get damaged it's just that you have to wipe them off often, so I'm looking to improve on the type of sensors, no suggestion made so far can work, the sensor already has a glass protection that can be unscrewed but water will still catch the glass and it will block the sensor at one point and it will still need to be wiped off, so that's why I'm wondering if I can't replace those sensors with types that don't need a reflector, something that won't be affected by water on its lens.

As already suggested, you could use a through-beam sensor, preferably with larger lens/window diameter than your presently used M18 sensor. But it will be still affected by water drops to some extent. Presumed the bottles are transparent, there's also a natural limit for increasing the sensor sensitivity. Continuously cleaning the sensor windows by compressed air has been already suggested, moving the sensors out of the wet zone or adding anti-splash screens seems more straightforward.

Cleaning by Compressed air under fast production will take too much time even though that mean sound weird to you guys, water is on the outer lens so all is needed is to wipe it off each time with a smooth cloth sensors cannot be moved since they are there to detect bottle locations to open and close gates if a bottles even drops or is badly lean then nozzles won't come down to fill bottles, moving sensors wouldn't work based on the machine design. Adding an anti splash screen sounds like the best idea even though I'm not so sure what it is in terms of form factor, how would I spruce that for sensors, if that would work then that would be the easiest method. The bottles are transparent but if thru beam sensors would face the same problem then that wouldn't work out either. Could you give me some info on the splash screen

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c_mitra said:

But don't you think that some arrangement that prevents water to come to the sensor will be better? Are you looking for something more than that?

Click to expand...

It would be best to stop water from coming to the sensors but there is alot of politics in that organization so I have to be skeptic on the type of changes I make to machines, production cant be stopped so it's hard to get time to troubleshoot certain things like that to see the real issue, but there is a series of machines from the comapny and I have issues with all of them, they are poorly designed to me and it's a money making scheme as far as I can see.

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KamalKumar said:

The closest that comes to mind is an ultrasonic sensor. It is water proof, rugged and reliable. Have a look at this - https://www.pepperl-fuchs.com/global/en/24176.htm. There could be other manufacturers.

Click to expand...

OK i see in spec for "UBE1000" sensor that it's output is PNP and for the sensor I'm replacing its NPN those wouldn't be able to work im assuming? Also I have some checks to do on the sensors at my place not sure if all 4 wires are being used, I doubt it but I have to check in other words if not I can get 2 wired sensors.

Hi,

Please focus on the problem.....

Give technical informations...not that much stories ;-)

Maybe try to ask some questions of my post#9.
There are several possible solutions depending on your answers.

Klaus

c_mitra said:

You can use a interruptive sensor that uses a light beam (like one in the old mouse) interruption but that means you need to put the source and detector at opposite sides. That may increase complexity. But how that will solve your problem? (anyway, I do not understand what is the real problem)

Click to expand...

It's a water bottling set up and production is always behind so every little thing to increase production is good, constantly as machines operate at each section operators have to be wiping off sensors if they happen to see it in time the machine will not pause right away if it misses a bottle or 2 so gates might close on bottles crushing them jamming some sections of the machine at times bottles bundle up after jamming and nozzles come down missing all the bottles necks and the nozzles are easily bent and that will take time to pull down the machine and straight or change nozzles all that is because the sensors get water on the lens and missed a count. Operators get used to the machines but at times they mess up and that spoils bottles and wastes time so my idea was to get another type of sensor that could take the water and which doesnt get affected by it, not sure if that actually exists.

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KlausST said:

Hi,

so is the sensor the problem or the reflector? Which one you have to wipe clean?

Is it clean, pure water or is there any cleaning agent or dirt in the water?

What causes the problems? is it caused by big water drops spilling around, or is it more like fog?

What length of clear distance do you have between the sensor and the bottles?

Is compressed air available in your system?

Klaus

Click to expand...

It is both the sensor and the reflector depending on how the water catches it, I don't think it's fog it's more the volume of water on it at times it blocks the beam.

The water is very clean ready to drink water.

Just based on memory the sensors have about 3 to 4 inches of clear space from bottles.

And yes Compressed air is available in the system.

Hi,

For big drops you may use a rotating window in front of the sensor
And the reflector itself could be rotating.
To see what I mean: https://m.youtube.com/watch?v=YPVBnBK09OM

Consuder to use a protecting tube (PMMA) in front of the sensor, maybe also for the reflector.
The inner diameter doesn't need to be much wider than the sensor area.

A short push of compressed air could wipe off drops from the lens.

Klaus