Operation Manual

8-15
IM 1F5B2-01E
8. MAINTENANCE
8.4.3 Instructions on Use of Check Terminals of Amplifier Unit
Test all the check items hereinafter discussed in this subsection at the test points
between terminals P and COM and between terminals TP2 and COM.
CAUTION
• Do not ground any test-purpose measuring instruments.
COM terminal
P termina
TP2 terminal
HHT terminal
Figure 8.4-1 Check Terminals of Amplifier Unit
(1) TP2 Terminal
■ Used for trigger level adjustment. See Subsection 8.2.3.
■ Using an oscilloscope, observe the voltage waveform appearing across terminals TP2
and COM. Make sure the ultrasonic emitter/detector of the sensor assembly and
related circuits are operating normally.
a. A waveform with the vortex frequency shown in Figure 8.4-2 should be observed at
this test point. The waveform should be neither at the power supply frequency nor
at a frequency at which the pipeline vibrates.
b.If piping conditions are inferior, the waveform should look like the one in Figure
8.4-3.
Figure 8.4-2 Normal Waveform at Terminal TP2