84
Reference Manual
00809-0100-4772, Rev FA
Troubleshooting
March 2016
Troubleshooting
Flow in pipe but
transmitter
indicates zero flow
Basics
Check to make sure that the meter is installed with the arrow in the direction of flow.
Check and verify configuration parameters in this order: K-factor, process fluid,
transmitter mode, fixed process temperature, fixed process density, density ratio,
pipe diameter, trigger level, low-flow cutoff, and low-pass corner frequency.
Check sizing. Make sure the predicted flow is within the measurable flow limits.
See Appendix C: Electronics verification for electronics verification procedure.
Possible application problems
Check signal_strength in the Transducer Block. Signal_strength should ideally be
greater than or equal to 4 to indicate a sufficient flow signal. If the number is below 4,
verify the “process density” is correct and the signal processing filters are optimized
for the process density. If the signal_strength is “zero” refer to the Vortex sensor and
remote sensor cable section below.
If the filters are set correctly and the signal strength is still weak (less than 4), it is
possible the actual flow is below the low flow cutoff setting. Lower the
low_flow_cutoff and/or the trigger. Monitor the signal strength again to see if it has
increased.
For liquid applications with the meter installed horizontally, verify the pipe is full.
Vortex sensor and remote sensor cable
If using a remote mount installation, inspect the black coaxial remote sensor cable
for cracks, cuts or other physical damage. If the cable is visibly damaged it should be
replaced. Note: The Vortex remote mount sensor cable is NOT field repairable.
Disconnect the remote sensor cable at the transmitter. Using an ohmmeter on its
highest range, measure the insulation resistance of the remote sensor cable by
measuring between the center conductor and the outer conductor. It should be
greater than 1 MΩ. If not, disconnect the remote sensor cable at the flow sensor.
Measure the cable again and see if the insulation resistance is greater than 1 MΩ.
Refer to Figure 7-17 and Table 7-3 on page 107 for detailed cable troubleshooting. If
less than 1 MΩ, the cable should be replaced. If it measures 1 MΩ or greater, then
measure the flow sensor resistance at the sensor SMA connector. It should read
greater than 1 MΩ resistance between the center conductor and the outer metal
jacket. If not, the sensor is defective and should be replaced.
If the Vortex sensor has been damaged by “water hammer” it may not be sitting on
the meter body post properly. The only way to verify this is to remove the sensor. See
7.5.4: Replacing the sensor.
Electronics
See Appendix C: Electronics verification for electronics verification procedure.
Table 7-1. Basic Troubleshooting
Symptom Corrective action
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