What type of sensor do I use?

[melaurint]

I am looking to measure a fiberous deposition that forms on a pressing roll. The thickness of the deposit ranges from 0mm at first, to 1mm thick and can cover the circumference of the roll uniformly or can form in a nonuniform blotchy fashion. The color of the deposition can range from white to brown against a dark colored roll surface. The roll is slow moving about 60 rpm.
I prefer to measure the roll on a continuous basis.

Thanks in advance

 

[nbucska]

What is the material of the deposit and of the roll ? <nbucska@pcperipherals.com>

 

[melaurint]

The roll can be made of hard rubber(red or white in color) or chrome. The material can be synthetic or paper fibers or a organic stickie substance. The build-up will be slow over time, anywhere from 15 minutes to an hour or longer.

 

[djs]

Hello;
How about an ultrasonic sensor? check out:

http://www.ab.com/catalogs/c114/3ultprox/30056.pdf

 

[melaurint]

Thanks for the info.
The Ultrasonic sensor looks promissing. However I think this models voltage output vs. target distance is much to low to detect a change of 1 mm. significantly. Am I wrong on this? Are there any more sensitive?

 

[djs]

Hello;
Perhaps if you don't need to actually measure the build up, just trigger an alarm if the buildup reaches a certain point, a capactive sensor might do:

http://www.ifmefector.com/usweb/zoomfun.nsf/ZoomData?readform&IA=KA0001&IB=&C=PS003&M=KA0001

 

[melaurint]

Thanks for the information djs.
I've ordered their catalog.
Is there a way to measure color change over time? The deposit does cause the roll to change color as the deposit layer builds up. I was taking pictures of the roll over time and measuring the color change using a program that can measure RGB value(Photoshop). I could then measure a % change from the original color, but this method is too labor intensive.

 

[IRstuff]

There are standalone color meters; I presume that there might be one that you could get serial data from.

TTFN

 

[IRstuff]

maybe something here?:

http://store.xrite.com/inandsys1.html

TTFN

 

[bobalou]

One I know of that will work is a non-contact,laser displacement sensor. They have been used in a broad number of industries for exactly your purpose.Here is the link:

http://www.keyence.com/products/displace.html?TLs=OC5