Theory 7
Agilent Nano Indenter G200 User’s Guide
7-4
Note that
S
has the dimensions of force per unit distance, and so it is
also known as the
elastic stiffness of the contact
.
Figure 7-2
Schematic of Load-Displacement curve
Hardness
The hardness (
H
) of the test surface is determined using the equation:
H = P/A
(5)
where
P
is the load applied to the test surface, and
A
is the projected
contact area at that load.
Elastic Modulus
The elastic modulus (
E
) of the test sample is determined from the
reduced modulus, E
r
, given by:
(6)
E
r
S
2
A
----------------
=
