2.
Connect ground rings, grounding electrode, lining protector, or grounding straps.
Grounding diagrams can be found in
.
3.
Verify the sensor is full.
4.
Verify wiring between sensor and transmitter is prepared properly. Shielding should
be stripped back less than 1 inch (25 mm).
5.
Use separate shielded twisted pairs for wiring between sensor and transmitter.
6.
Properly connect the wiring between the sensor and the transmitter. Corresponding
terminal block numbers in the sensor and transmitter must be connected.
12.4.3
Troubleshooting high process noise
Note
In applications where very high levels of noise are a concern, it is recommended that a dual-
calibrated Rosemount High-Signal 8707 sensor be used. These sensors can be calibrated to run at
lower coil drive current supplied by the standard Rosemount transmitters, but can also be upgraded
by changing to the 8712H High-Signal transmitter.
1/f noise
This type of noise has higher amplitudes at lower frequencies, but generally degrades over
increasing frequencies. Potential sources of 1/f noise include chemical mixing and slurry
flow particles rubbing against the electrodes. This type of noise can be mitigated by
switching to the 37Hz coil drive frequency.
Spike noise
This type of noise generally results in a high amplitude signal at specific frequencies which
can vary depending on the source of the noise. Common sources of spike noise include
chemical injections directly upstream of the flowmeter, hydraulic pumps, and slurry flows
with low concentrations of particles in the stream. The particles bounce off of the
electrode generating a “spike” in the electrode signal. An example of this type of flow
stream would be a recycle flow in a paper mill. The type of noise can be mitigated by
switching to the 37Hz coil drive frequency and enabling the digital signal processing.
White noise
This type of noise results in a high amplitude signal that is relatively constant over the
frequency range. Common sources of white noise include chemical reactions or mixing
that occurs as the fluid passes through the flowmeter and high concentration slurry flows
where the particulates are constantly passing over the electrode head. An example of this
type of flow stream would be a basis weight stream in a paper mill. This type of noise can
be mitigated by switching to the 37Hz coil drive frequency and enabling the digital signal
processing.
Noise ratio less than 25 in 5 Hz mode
The transmitter detected high levels of process noise. If the signal to noise ratio is less than
25 while operating in 5 Hz mode, proceed with the following steps:
Troubleshooting
Reference manual
163
Содержание Rosemount 8732EM
Страница 2: ......
Страница 6: ...Contents iv Rosemount 8732EM Transmitter with HART Protocol Reference Manual ...
Страница 10: ...Safety messages 4 Rosemount 8732EM Transmitter with HART Protocol Reference Manual ...
Страница 14: ...Introduction 8 Rosemount 8732EM Transmitter with HART Protocol Reference Manual ...
Страница 30: ...Sensor Installation 24 Rosemount 8732EM Transmitter with HART Protocol Reference Manual ...
Страница 87: ...Field Communicator Dashboard Menu Tree HART v5 4 part 2 Figure 7 8 Operation Reference manual 81 ...
Страница 92: ...Operation 86 Rosemount 8732EM Transmitter with HART Protocol Reference Manual ...
Страница 138: ...Advanced Diagnostics Configuration 132 Rosemount 8732EM Transmitter with HART Protocol Reference Manual ...
Страница 158: ...Maintenance 152 Rosemount 8732EM Transmitter with HART Protocol Reference Manual ...
Страница 214: ...Product Certifications 208 Rosemount 8732EM Transmitter with HART Protocol Reference Manual ...
Страница 217: ...Wiring 8732EM using combination cable Figure C 2 Wiring Diagrams Reference manual 211 ...
Страница 221: ...Wiring Diagram 475 Field Communicator with 8732EM External Analog Power Figure C 6 Wiring Diagrams Reference manual 215 ...
Страница 222: ...Wiring Diagrams 216 Rosemount 8732EM Transmitter with HART Protocol Reference Manual ...
Страница 253: ...Implementing a Universal Transmitter Reference manual 247 ...