First specimen to come in contact, first with the pressure foot and later with the indenting tip under the specified contact load. Further movement of the platform causes the indenting load to act on the test specimen. Penetration of the indenting tip into the test specimen is determined with the help of a dial gauge fitted at the top of the pressure foot assembly. The contact between the dial gauge and the top of the plunger rod is made through an electrical arrangement to ensure that the weight of the stem of the dial gauge does not act on the test specimen. An electric buzzer is provided to slight vibrations to the plunger rod to eliminate friction. The dial gauge gives the depth of indentation in units of 0.01 mm which can be converted into IRHD hardness value.

First specimen to come in contact, first with the pressure foot and later with the indenting tip under the specified contact load. Further movement of the platform causes the indenting load to act on the test specimen. Penetration of the indenting tip into the test specimen is determined with the help of a dial gauge fitted at the top of the pressure foot assembly. The contact between the dial gauge and the top of the plunger rod is made through an electrical arrangement to ensure that the weight of the stem of the dial gauge does not act on the test specimen. An electric buzzer is provided to slight vibrations to the plunger rod to eliminate friction. The dial gauge gives the depth of indentation in units of 0.01 mm which can be converted into IRHD hardness value.