GE General Electric Oxygen Equipment PT878 用户手册

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Chapter 8. Servicing the PT878
168
Transport® Model PT878 Portable Liquid Flowmeter User’s Manual
8.4.5 Calculating Velocity (Pipe Material Soundspeed)
The nominal soundspeed for your pipe material will give 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 
soundspeed differs from the soundspeed of the material 
used in the calibration block. It is possible only if you have 
a sample of pipe material with 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 113: Soundspeed Window
1.
Scroll to the Velocity tab as shown in Figure 113 above. Pres
[ENTER]
.
Display
Thickness Gauge Measure
Cancel
OK
Velocity
Graph
Zero
Material
Block Length
0
Calculated
Current
Determine the Sound Speed