①
Gain step
②
Gain step max
③
Gain step min
④
Transducer distance [mm]
Figure 9-2
SITRANS FUS080 Gain step vs. Transducer distance
Gain step
The graph above shows which gain step to expect for a particular transducer 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 transducers in clean water, but takes into account the
expected variance from the converter and the transducers.
Gain step error conditions
Condition
Cause
15
● No transducer (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
FUS380/FUE380
76
Operating Instructions, 09/2016, A5E00730100-AB