Determining Contact Stiffness Dynamically - Agilent Technologies Nano Indenter G200 User Manual

Determining Contact Stiffness Dynamically

Agilent Nano Indenter G200 User's Guide
It is important to note that in general, the contact stiffness, S, is required
for the determination of elastic modulus and hardness because it is used
in the calculation of the projected contact area, A. The Continuous
Stiffness Measurement (CSM) option allows the continuous
measurement of the contact stiffness during loading and not just at the
point of initial unload. This is accomplished by superimposing a small
oscillation on the primary loading signal and analyzing the resulting
response of the system by means of a frequency-specific amplifier. With
a continuous measure of S, one obtains the hardness and elastic modulus
as a continuous function of depth from a single indentation experiment.
Theory and details of operation are provided with the documentation for
the CSM option in Appendix A, "Continuous Stiffness Measurement".
Theory 7
7-8