Emerson Rosemount 8782 Reference Manual page 133

Reference Manual
00809-0100-8782
4. Verify wiring between sensor and transmitter is prepared properly. Shielding should
5. Use separate shielded twisted pairs for wiring between sensor and transmitter.
6. Properly connect the wiring between the sensor and the transmitter.
12.4.3 Troubleshooting high process noise
Note
For more information about process noise, see
1/f noise
This type of noise can be mitigated by switching to the High frequency coil drive setting.
Spike noise
The type of noise can be mitigated by switching to the High frequency coil drive setting,
and enabling the Increased, Maximum, or Custom signal processing modes.
White noise
This type of noise can be mitigated by switching to the High frequency coil drive setting,
and enabling the Increased or Custom signal processing modes.
Noise ratio less than 25 in Low coil drive frequency mode
The transmitter detected high levels of process noise. If the signal to noise ratio is less than
25 in Low coil drive frequency mode, proceed with the following steps:
1. Increase transmitter coil drive frequency mode to High (refer to
2. Verify sensor is electrically connected to the process with process reference
3. If possible, redirect chemical additions downstream of the magmeter.
4. Verify process fluid conductivity is above 50 microSiemens/cm.
Noise ratio less than less than 25 in High coil drive frequency
mode
If the signal to noise ratio is less than 25 in High coil drive frequency mode, see
Signal
Reference Manual
be stripped back less than 1 inch (25 mm).
Corresponding terminal block numbers in the sensor and transmitter must be
connected.
and, if possible, perform auto zero function. See
electrode, grounding rings with grounding straps, or lining protector with
grounding straps.
Processing.
Process noise profiles.
Coil drive frequency
Auto zero).
Troubleshooting
November 2019
Digital
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