Emerson Rosemount 5408 Reference Manual page 112

Service and troubleshooting
February 2020
Table 7-6: Incorrect Level Readings
(1)
Symptom
When the product surface is near the
sloped tank bottom, the transmitter enters
alarm mode.
(1) = actual level
7.3.2 Troubleshooting the 4-20 mA/HART
Table 7-7: Troubleshooting the 4-20 mA/HART Output
Symptom
Transmitter milliamp reading is zero.
Transmitter milliamp reading is too low or high.
Milliamp reading is erratic.
112
(continued)
Possible causes
Reduction of projected
surface area close to sloping
tank bottom.
Time
= reported level
Recommended actions
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Recommended actions
• Verify the tank geometry parameters
are configured correctly (especially the
Reference Height and Bottom Offset).
• If measurement in this region is not
crucial, increase the Empty Tank
Detection Area, see
handling.
• Verify the Bottom echo visible when
tank is empty parameter is disabled,
see Enable bottom echo visible when
tank is
®
Verify power is applied to signal terminals.
Verify power supply voltage is adequate at signal terminals,
see Power supply.
Verify transmitter and power supply are properly grounded.
Verify level.
Check the settings of the 4-20 mA range values, see
lower range value.
Verify output is not in alarm condition.
Check that power wires are connected to the correct signal
terminals.
Perform Calibrate Analog Out, see
Verify power supply voltage is adequate at signal terminals,
see Power supply.
Check for external electrical interference.
Verify transmitter is properly grounded.
Verify shield for twisted pair is only grounded at the power
supply end.
Under turbulent conditions with low level rates, consider
increasing the Damping value.
Reference Manual
00809-0100-4408
Empty tank
empty.
Output
Upper/
Calibrate analog out.
Reference Manual