Emerson Rosemount 5408 Reference Manual page 105

Table 7-6: Incorrect Level Readings
(1)
Symptom
Measured level is correct at 0% (4 mA) but
incorrect at 100% (20 mA).
Incorrect level when the product surface is
above the 50% level.
Measured value drops to zero level.
Rosemount 5408 and 5408:SIS Level Transmitters
(continued)
Possible causes
Upper Range Value is not set
correctly.
Time
Strong double bounce echo
that is interpreted as the
product surface.
Time
Transmitter has locked on a
strong tank bottom echo.
Time
Service and Troubleshooting
Recommended actions
Check that the Upper Range Value match-
es the 100% (20 mA) level in the tank.
Enable the Double Bounce Handling func-
tion, see Section 7.5.4.
• Verify the Reference Height is config-
ured correctly.
• Enable the Tank Bottom Projection
function, see
Use tank bottom projection.
• Enable the Bottom echo visible when
tank is empty parameter, see
Enable bottom echo visible when tank is
empty.
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