NDT Systems Bondascope 350, Руководство оператора

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Bondascope 350 Operator's Manual
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10.10 Material Temperature Effects:
The dimensions, ultrasonic velocity, and surface flexural properties of a material change with temperature, which, in
turn affect the inspection. An area in the sun will likely exhibit a different NULL than that in the shade for instance.
Again, Signature mode can help even out the appearance of NULL offsets.
The situation becomes more complex when the material temperature is considerably different than ambient. One
solution is to calibrate on a reference sample at the same temperature as the material. Another solution is to calibrate
on a reference sample at ambient temperature and then add an experimentally derived correction factor for the
temperature of the material.
10.11 Excessively Attenuative Materials:
Some materials (fibrous, porous, large-grained, etc.) may absorb or scatter so much ultrasound that either a reading
cannot be obtained or some abnormal reading (usually abnormally thin) occurs. These types of materials require the
higher power capabilities of the Bondascope 3100 in conjunction with a Special Low Frequency, High Power Probe.
10.12 Honeycomb Cell Shape on Directionality Effects:
In structures where the cell of the honeycomb is not symmetrical it is advised to keep the probe in the same relative
orientation as that when the probe was NULL(ed), particularly while in the phase or Mode 2. The transit time and
flexural properties are different in either orientation. Once again, the shifts in phase are greatly reduced in appearance
in the signature mode. Experimentation will demonstrate this anomaly.