Light/dark sensors?

[gerard]

Hi,

Just wondering if anyone can recommend a sensor that can distinguish between a bright surface and a darker surface? The bright surface is White as
in White bread colour. The background is darker, it's brown in colour.
The bread is flat so I can't just use a sensor that can detect a product.

Cheers

 

[SirKit Breaker]

Leuze do one that can do that, cant remember the model, but it is switchable from light on, dark off, to light off dark on, and it has sensitivity adjustment. i know of an application where they are used on high speed packing machines to detect a clear gap in printed film to give a signal to a cut knife to cut in the gap. I think CEF do them or RS.

Cheers........Howard

 

[mikejashley]

Most sensors have a Lon / Don facility, omron lenze baumer are just a few to name however they may still pick up on the white of the bread and cause spurious errors. Beter are colour sensors or light intensity sensors where you can set the sensitivity according to different products and will allow for a lot more variation see HistoryRS Components | Electronic and Electrical Components

for details (shopping elsewhere you will be able to find cheaper)

 

[silva.foxx]

Have a look into 'direct-detect with background suppression' sensors... or distance sensors.

Lots of brands to pick from. I'll add Keyence, Sick, IFM, Balluff, Sunx and Datalogic to the list.

Is it important to sense the "white" of the bread or just to see that bread is there?

.

 

[Leuzeelectronic]

Hi,

We at Leuze electronic have just joined this forum but hopefully this reply will still be of interest. A good background suppression sensor such as a HRTR3B should be fine as the target is white and the background is dark. Otherwise a contrast sensors such as KRT3B may be suitable. We would be happy to loan you sensors for tests if you can provide details of range etc.

Full details of the sensors can be found on www.leuze.co.uk