Siemens SITRANS LUT400 - Page 277

SITRANS LUT400
Operating Instructions, 07/2019, A5E33329501-AC
275
Symptom
Possible Cause
Action
Calibration required If accuracy is better when level is close to
transducer, and worse when level is far from
transducer, perform calibration [see Auto
Sound Velocity (2.12.1.6.) (Page 219).]
If accuracy is consistently incorrect, use Sen-
sor Offset (2.2.3.) (Page 172) or perform
calibration [see Auto Sensor Offset (2.2.6.)
(Page 173)].
Reading erratic Transducer mounting:
wrong location or incor-
rectly mounted
Ensure beam has a clear path to material
surface;
Verify transducer is not too tight;
Use an isolation coupling.
Unavoidable false echoes
from obstructions
Use Auto False Echo Suppression. See Auto
False Echo Suppression (2.12.3.1.)
(Page 222).
Confidence too low Check Noise, Echo Strength, Confidence.
See Echo Quality (3.2.9.) (Page 244).
Check LOE Timer is not set too short. See
LOE Timer (2.4.2.) (Page 175).
Multiple echoes Check mounting location; Verify material is
not entering Near Range zone. See Near
Range (2.2.4.) (Page 172).
Noise in the application Verify source and minimize. See Noise Prob-
lems (Page 276).
Incorrect reading (mA
output and/or displayed
value)
mA function not assigned
to correct measurement
Check mA assignment. See Current Output
Function (2.5.1.) (Page 176).
When device configured
for flow: exponent or
breakpoint not correctly
selected
Check configuration: if Sensor Mode (2.1.2.)
(Page 168) set to FLOW, verify correct expo-
nent [Flow Exponent (2.15.3.2.) (Page 231)]
and breakpoints [Universal Head versus Flow
(2.15.5.) (Page 236)].
Incorrect vessel or PMD
dimensions
For volume application: Verify vessel dimen-
sions. See Vessel Shape (2.6.1.) (Page 180).
For flow application: Verify PMD dimensions.
See PMD Dimensions (2.15.4.) (Page 234).
Relay not activating
Relay not programmed
Program relay.
Relay incorrectly assigned Verify with simulation. See Simulation (3.4.)
(Page 258).
Incorrect relay function
selected
Verify with simulation. See Simulation (3.4.)
(Page 258).
Incorrect relay setpoints
Verify setpoints.
Relay not activating
correctly
Relay incorrectly assigned Verify with simulation. See Simulation (3.4.)
(Page 258).
Incorrect relay function
selected
Verify with simulation. See Simulation (3.4.)
(Page 258).
Incorrect relay setpoints
Verify setpoints.