Dwyer UFB - Manual (Page 40)

5: Troubleshooting
36
• Very hot pipe almost turns water to steam and therefore exhibits the wrong speed characteristics –could
be due to reduced pipe pressure.
• Flashover – liquid turns into a gas because of lower than required pressure.
5.2 General Troubleshooting Procedure
Figure 5.1 Troubleshooting chart
Is the display blank?
Loss of power supply.
Confirm power supply availability.
(note: if using 24V power supply,
the internal fuse should reset
when power is removed)
No
Turn instrument OFF/ON.
If the display is still scrambled/
hung up, return the instrument for
repair.
Yes
Is the display
scrambled or
hung up?
Yes
Measurement differs from expected value. Unstable measurements. No (or poor) signal.
Problem probably due to non-constant fluid flow.
Check the following:
- the pipe data has been entered correctly.
- the fluid type has been entered correctly.
- the correct transducer type has been selected.
- the pipe diameter is within specifications of the
selected transducers.
- the pipe is completely full.
- the pipe surface is not corroded, or protective
surface loose.
- no particles in the fluid.
Ensure the temperature is set correctly.
Ensure that the transducer cables are connected
correctly.
Ensure transducers are positioned in accordance
with the recommended distance from bends etc.
Ensure flow velocity >0.01m/s.
Ensure that sufficient acoustic couplant has been
applied to the transducers.
If triple reflex mode is selected, try selecting
double or single reflex instead.
No
START
Are any
status messages
shown?
No
Note any active messages.
Refer to the message table in this
chapter to interpret the message
and view suggested response.
Yes