Drying shrinkage

[sherwood34]

I need to measure the shrinkage of a ceramic body as it dries. The tricky part is doing this while the body is being subjected to microwave energy. I have done this in the past by removing the part and measuring with calipers...but I'd really like to measure in-situ. Any thoughts?

One other thing...I'm also trying to ensure uniform drying so I can eliminate differential shrinkage confounding my measurements.

 

[metman]

Maybe you could grasp the body with plastic dial calipers and attach a non-metallic extension spring to keep the calipers in contact with the body as it shrinks. Or are the shrinkage units in microns or at some other level not measurable with dial calipers?

 

[sherwood34]

Contact measurements have a tendency to deform the batch, so I'm attempting to find a laser micrometer or other non contact measurement device. I'm also trying to measure weight loss simultaneously to build a shrinkage vs. weight loss curve. This is harder than I ever expected it to be.

 

[Compositepro]

A laser interferometer or a laser triangualtion system can do what you want but they will be pricey and you have to know what your doing to make them work right. I would use a dial indicator and a glass rod for a probe extension. It will be far cheaper and simpler. Keep the rod tip diameter small so it doesn't influence your measurement too much.

 

[sherwood34]

I really need a non-contact measurement...the batch deforms too easily.

Isn't there anything out there that serves as a non-contact micrometer that isn't real pricey? Seems like there would be....?

 

[Compositepro]

You can check out

http://www.keyence.com/topics/vision/lk/guide.php#more

They are pretty big in the field.