Thin samples are notoriously difficult to test. This is a short guide with some tips to make your thin sample testing more accurate and repeatable.
Compression or penetration
When
testing the hardness of thin products by compression or penetration,
the measured force may show a sudden exponential increase as shown in
the graph below. This occurs as a result of the probe moving nearer to
the base.
Either the test will abort because the load cell has
overloaded, or the test will finish, collecting irrelevant data that
does not reflect the true properties of the product. Comparison could
then incorrectly be made between maximum forces that are not sample
derived.