April 2004
9-12 Servicing the PT878GC
Calibrating the Thickness Gauge Transducer
To zero the transducer offsets, go to the Zero tab. Press the [W ]
or [X] arrow key until you reach the Zero tab and press [ENTER].
The screen appears similar to Figure 9-9 below.
Figure 9-9: The Zero Window
1. Press the [T] arrow key to enter the window.
2. The first prompt asks you to choose between single and dual-
point calibration. Use the [W ] and [X] arrow keys to move
to the appropriate radio button and press [ENTER].
Note: GE Panametrics recommends dual calibration. Dual-
point calibration is more reliable, but it re quires two
known thicknesses of the calibration material.Use single-
point calibration only if you know the sound speed in the
calibration block material to a high degree of accuracy.
See Appendix C for more information.
3. The next prompt asks you to enter the length of Block 1. (If
you are using a GE Panametrics-supplied test block, the length
is printed on the block.) Press [ENTER] to open the text box.
Display
Thickness Ga uge Measure
Cancel OK
Graph Velocity Zero
Material
Block 1 Length
Calculated Current
Transducer Delay,
0 0
Single Dual Calibration
0mm Calibrate