Curve—Care should be exercised that the peak
or peaks reported are real and not artifacts of the impact test or
inertial effects. This is especially true when brittle failures are
encountered. The impact can produce inertial effects along with
excitation of the natural frequencies of the transducer/probe/
test device/specimen combination and since the “ringing” is
added to the test data, significant errors can occur. If the
multiple peaks of the unfiltered or unsmoothed test curve are
approaching the natural frequency of the force measuring
system, the validity of the data should be investigated