Appendix A: Verification And Calibration - Triax 2015 User Manual

APPENDIX A
TRIAX 2015 VERIFICATION PROCEDURE AND CALIBRATION
A.1 Why use a reference pad?
The measurements made by the Triax2015 are not easy to duplicate using other test
equipment. As such there must be a means for a user to ensure that the instrument is
working properly between factory calibrations. When a Triax 2015 is manufactured and
tested at the factory and is in a known good condition, a series of drop tests are performed
on a 8 inch (203 mm) square reference pad. The pad is then supplied with the respective
Triax 2015 system and whenever the pad is retested by the user the results should agree,
within an established tolerance, with results originally obtained at the factory.
A.2 Establishing Initial Reference Pad Values
Subsurface conditions (i.e. the hardness and thickness of concrete) will affect the
reference pad values and yield different values than the factory values. To fully utilize the
reference pad, initial reference pad values for a particular subsurface must be obtained.
There are no user accessible means of performing calibration adjustments.
NOTE: The reference pad must be stored at normal room temperature and humidity
conditions in order to provide reliable results. After transport or storage involved
extended temperature or humidity allow the pad to acclimate to normal room condition
for at least 12 hours.
A.2.1 Place reference pad on a bare concrete surface (no carpet or tile, painted is fine)
A.2.2 For a Triax 2015 E missile erect the tripod and position the missile that the bottom
of the missile is 36" +/- ¼" (915mm +/- 5mm) above the surface of the reference mat.
For a Triax 2015 "A" missile system the drop height is 24" +/- ¼", and is measured from
the surface to the center of the release knob.
A.2.3 Perform three drop tests, waiting 1.5 minutes ±30 seconds between drops,
averaging the Peak G and HIC results of the second and third drops. This average Peak G
and HIC are the Initial Reference Pad Averages and should be recorded on the Reference
Pad Data Record for future use. The measured Peak G should agree within +/-10% of the
average of the Peak G of drops 8 and 9 on the factory calibration report, ensuring that the
system was not damaged during shipment or storage. The +/-10% window compensates
for differences in the concrete floor between the factory and the user's locations.
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