Siemens SITRANS FUS380 - Page 84

① Gain step
② Gain step max
③ Gain step min
④ Sensor distance [mm]
Figure 9-2 SITRANS FUS080 Gain step vs. Sensor distance
Gain step
The graph above shows which gain step to expect for a particular sensor distance (face to face
distance). The upper curve indicates the upper limit and the lower curve indicates the lower
limit.
The graph applies to perfectly aligned sensors in clean water, but takes into account the
expected variance from the converter and the sensors.
Gain step error conditions
Condition Cause
15
● No sensor (e.g. defective cable)
● Empty pipe
High values
● High damping (e.g. inhomogeneous media)
● Unsuitable medium
● Path angular misalignment
Unstable/fluctuating values
● Air bubbles or solids in medium
● Bad inlet conditions
Δ gain step between path 1 and path 2 > 1
(2-path systems only)
● Bad inlet conditions
● Inhomogeneous medium
● Path angular misalignment
Troubleshooting/FAQs
9.2 Diagnosing with PDM
SITRANS FUS380/FUE380
84 Operating Instructions, 05/2018, A5E00730100-AE