rubber testing

[kukku]

All the standards talk of testing the hardness (in case of rubber) on test specimens. Is there a way to check the hardness on the very small irregular parts (not specimens)? The requirement is on Shore A scale.

 

[BLN]

You can test Shore A on irregular objects, but the problem that arises is non-repeatable results. I've used a hand held durometer, and to measure the hardness I needed a flat surface so the durometer wouldn't "roll" on the sample and give erroneous readings.

If the readings you need are more for your information, an irregular shape should give a close reading. If you're using the info to report, you should make a flat witness panel from which to get your readings.