Emerson 8800C - Tp1

4-7
Hardware and Software Maintenance and Troubleshooting
Figure 4-2. Signal Flow
TP1 TP1 is the vortex shedding signal after it has gone through the charge
amplifier and low pass filter stages and into the input of the sigma delta
A-to-D converter ASIC in the electronics. The signal strength at this point
will be in the mV to Volt range.
TP1 is easily measured with standard equipment.
Figures 4-3, 4-4, and 4-5 show ideal (clean) waveforms and waveforms
that may cause the output to be inaccurate. Please consult the factory if
the waveform you detect is not similar in principle to these waveforms.
8800-0572D
Sensor
Charge
Amplifier
Amplifier/
Low Pass
Filter
A-to-D Converter
Containing Frequency
Generator
External
Test
Frequency
Input
TP1 Shedding Frequency Output
Digital Filter
Microprocessor