As the hardness tester is pressed against the sample, the material resistance force and indentor spring load balance. The depth of the indentor is measured, which provides a measure of the material's hardness. Values are based upon a 100 point scale (accuracy .75 point). However, as time elapses the indicator will "creep" back so that a reading taken a few seconds after the tester makes contact with the sample will be less than the peak reading. The optional peak indicator helps to more closely monitor the difference between peak and "creep" in hardness tests.