Setting The Zero Value Of The Probe - NDT Systems TG-900+ User Manual

2.4.2 Setting the zero value of the probe

In order to exclude the sound pulse transit time in the time-delay circuits on the thickness measurement
result — it is advisable to set the zero of the connected probe before conducting measurement, for
doing so, the user needs to:
1. Set the parameters of the reference sample (the ultrasound propagation speed and the thickness
value of the sample), using which the zero value is going to be set. The reference sample
parameters are set in the "SETTINGS" (see 2.3.4.).
Warning!
Preliminary calibration of the probe should be carried out only on the sample (measure) built-in
the thickness gauge.
2. Enter the "MEASURING" menu, press the "
3. Clean the probe contact surface of contact fluid, if any.
4. Rise the probe to air, according to the "ON AIR" instruction on the display (Fig. 2.20), after which
approve the action conduct by pressing the "
5. The device then will conduct the measurement and display a new "SET ON THE SAMPLE"
instruction (Fig. 2.21).
6. Apply a layer of the contact fluid to the reference sample.
Note – It is advisable to use a couplant without mechanical impurities and solvents (solvent,
gasoline, diesel, kerosene, etc.), as they damage probes and connection cables.
7. Apply the probe with the contact surface on the reference sample and seal it against it, according
to the "SET ON THE SAMPLE" instruction, after which approve the action conduct by pressing the
" " key.
18 | NDT Systems, Inc.
P a g e
Figure 2.20 – The "ON AIR" instruction
Figure 2.21 – The "SET ON THE SAMPLE" instruction
300 Innovative Way Suite 222
TG-900+ User Manual
" key, and choose the "CALIBR".
" key.
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