GE PT878GC Manual De Usuario
April 2004
9-14
Servicing the PT878GC
Calculating Velocity (Pipe Material Sound Speed)
The nominal sound speed for your pipe material will give
thickness measurements of reasonable accuracy. However, for
greater accuracy, calibrate pipe material sound velocity.
thickness measurements of reasonable accuracy. However, for
greater accuracy, calibrate pipe material sound velocity.
IMPORTANT: This step is necessary only if the actual pipe
material sound speed differs from the sound
speed of the material used in the calibration
block. It is possible only if you have a sample of
pipe material with the thickness known to a high
level of precision.
speed of the material used in the calibration
block. It is possible only if you have a sample of
pipe material with the thickness known to a high
level of precision.
To open the Velocity window, press the [
W
] or [
X
] arrow key
until you reach the Velocity tab and press
[ENTER]
. The screen
appears similar to Figure 9-10 below.
Figure 9-10: The Sound Speed Window
1. Scroll to the Velocity tab as shown in Figure 9-10 above.
Press [ENTER].
Display
Thickness Gauge Measure
Cancel
OK
Velocity
Graph
Zero
Material
Block Length
0
Calculated
Current
Determine the Sound Speed