Checkline TI-007DLX, Руководство по эксплуатации

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6.0 THROUGH PAINT MEASUREMENT
6.1 Introduction
Through paint measurement is accomplished by measuring the time between two repeat
echoes from the back surface of the material. Since both of these back wall echoes travel
the same path through the paint or coating, the thickness of the coating is subtracted out
of the measurement so that only the actual material thickness is measured. This avoids
having to scrape or remove the coating from materials prior to inspection. The primary
purpose of thru paint measurement is to determine the actual/nominal material thickness
without error from the coating. Finally, this mode will only work for typical epoxy
based coatings.
6.2 Multi Mode Transducers
The multi echo measurement technique does have restrictions on the type of dual
element transducers it can use successfully. The key requirement is that the transducers
are “highly damped”, which refers to the duration of how long the transducer rings. In
order to improve the low end measurement range, ability to measure thin materials, the
cycles of ring down must be limited so they don’t interfere with the internal gating.
Since the TI-007DLX is a basic easy to operate gauge without the adjustability you’d get
using an advanced A-Scan scope, echo-echo mode is subject to limitations depending on
type and thickness of the coating, as well as the type of transducer used.
The procedure for activating the through paint (E-E) measurement mode is
outlined as follows:
NOTE:
Be sure that a probe zero and “one point calibration”, or a “two point
calibration” has been performed prior to this procedure.
1. Press the key to toggle between the measurement modes; pulse-echo (P-E)
and echo-echo (E-E) at any time.
NOTE:
An icon will be illuminated in the top left portion of the display to indicate the
measurement mode the TI-007DLX is currently using.