Section 1
Ref: REFLEX/SCANFLEX MANUAL
EDITION 1: JULY ’97 40
I) Analogue output does not correspond to application:-
1. Check that the correct options (Pr.30 to Pr.33) have been selected.
2. Check that the correct span (Pr.5) has been input, this is the value over which
the analogue will be spanned unless a separate entry has been made at Pr.32
or Pr.33.
J) Display stays high:-
* This is usually caused by return echoes from close-in obstructions.
1. Check for obstructions. If the transducer is mounted in a standpipe, check for
rough edges at connection with the vessel, refer to Page 47.
2. If there are no close-in obstructions ensure that the isolation kit (Pages 50-52)
is fitted on the transducer and the transducer is mounted correctly. The
isolation kit should enable the transducer to move slightly, it should not be
solid. (Not applicable if the transducer has an integral flange).
3. May be caused by rate of change, Pr.7 being too small.
4. Check the entry at Pr.6. This should not be less than the factory default value.
K) Display is lower than expected:-
1. Check that Pr.4 and 5 are correct for the application.
2. It can be caused when the level rises into the blanking zone (Pr.6). The system
may lock-up on a multiple echo and track this value when the level falls. The
correct reading can be re-established by pressure 'MODE-1-MODE' but to
effect a permanent cure, the transducer should be raised to prevent the level
encroaching into blanking.
3. It can also be caused by poor surface quality. On liquid applications this may
be foam or turbulence and on solids, a very irregular surface.
4. The level may be moving at a faster rate than that programmed in Pr.7. The
rate of change value should be increased to match the true rate.
L) Display changes in steps:-
Increase rate of change at Pr.7 to match the true rate.
M) Display is inaccurate:-
1. Check the empty distance at Pr.4.
2. Check the vessel dimensions and any volume conversion factor used at Pr.43.
3. Temperature compensation may be required.
4. The presence of vapours will affect accuracy. If they are constant over the
range, the speed of sound can be adjusted at Pr.69.
5. Check that the echo processing routine at Pr.68 is correct for the application.
To Next Page
Loading...
Need help?
General
