anyone work in a bottling environment?

There are several ways to do this - what exactly are you trying to pick up? Bottle-caps? Labels? or just the presence/adsense of a bottle??

Have a talk to someone at Sick

- these are the only photo-electrics I have never had a problem with and I know they have a few units in their range that can do this.

Cameron:-)

If by retro-reflective you mean one that looks at a reflective target then the problem is more likely it seeing straight through the bottle than it seeing a reflection from the bottle.

Assuming the bottles are cylindrical...

If the bottles stop in a fixed position then you could aim the beam at the first or last quarter of the bottle. Hitting the glass at an angle a proportion of the beam will be reflected away which may give enough difference for you to reliably detect.

If the bottles don't stop at a fixed position then you may be able to angle the beam downwards or upwards for he same effect. If the bottles are short you might not be able to get enough angle.

I mean a sensor that points at a reflector and goes from light to dark when a bottle passes between sensor and reflector. The problem is that when bottles are passing the sensor it should be dark but sometimes when the bottles pass they switch to light momenterilly causing too many bottles to be fed in. I know it's a reflection because it happens even if the reflecter is covered

The bottles don't stop at all. a

Yeah I tried that. left to right too at least as far as I can. I was really hoping somebody had had this problem and found a sensor that worked all the time.

I'm trying to get a sensor to stay dark when the conveyor is full of clear glass bottles. Trouble is if it intermitently goes light due to a reflection from a bottle the plc calls for extra bottles. Debounce won't help either for other reasons. I really need the sensor to work.

Funilly enough one of our engineers had one of their guys in and showed him the problem. He tried his kit and had the same issue without a resolution.

Where does the reflection happen? Is it just when the bulge of the bottle passes by, or just at the edge? If just one of these is the case then having two sensors spaced apart by around 1/2 of the bottle diameter and requiring _both_ of them to show reflections might correct your problem.

hmmm. sounds like a solution. Pricey but a solution. Cheers Tim

There's something to be said for a microswitch or other contact sensor.

A reflection will be somewhat diffuse. I solved a problem like yours once by using a specular reflector instead of a retroflector -- a PITA to set up -- and lens to bring the light through a small hole to the sensor. Distorting or deflecting the beam gave the same indication as blocking it.

Jerry

Well, try this:

I was going to suggest choosing a wavelength where glass is opaque, like high UV or 10 micron infra red, with matching emitters, reflectors, detectors, and of course training the manufacturing crew on the invisible beam.

There, now doesn't a pair of visible-light sensors look like an inexpensive solution?

I'll certainly look at it. Many thanks

Tried this with a rats tail limit switch. The problem is the lag between bottle touching actuator and contacts closing allows gaps between bottles which mean fallen bottles further down due to lack of pressure.

"Bob Watkinson" wrote in news:d4mb78$fmm$ snipped-for-privacy@news8.svr.pol.co.uk:

How about a capacative proximity switch?

Scott

Range no good, too short but cheers anyway Scott

"Bob Watkinson" wrote in news:d4omdv$6mt$ snipped-for-privacy@news6.svr.pol.co.uk:

How about a photoelectric Omron E3S-CR, for transparent glass, with claims to not be bothered by lens effects. It has a 10cm range.

Scott

Yeah thanks Scott I think Ill get Omron in to give there kit a try.

use contrinex urs1180c303 retroreflective ultrasonic. any perpendicular object can be used as a "reflector"

best wishes joe

But they won't work on curved bottles Joe. Flat object only with ultra sonics surely.

how bout SUNX LA-300 series LED Collimated beam sensor...sounds good too!

Now there's a use for frosted bottles!

There are laser ranging devices, some cheap enough for a carpenter's tool box. If the distance doesn't match the known retroflector location, it's not a gap.

Jerry

Jerry Avins wrote in news: snipped-for-privacy@rcn.net:

That would take his control solution from a simple digital input to something much more complex

Scott