Emerson Process Management 8732 Table 6-5. Sensor Test, -------------------------------=, ----------------------------=, 1nanosiemens 1 1gigaohm, 1nanosiemens 1 110, 9ohm

Reference Manual
00809-0100-4663, Rev BA
January 2010
Rosemount 8732
6-8
To test the sensor, a multimeter capable of measuring conductance in
nanosiemens is preferred. Nanosiemens is the reciprocal of resistance.
or
Table 6-5. Sensor Test
Test Sensor
Location Required Equipment Measuring at Connections Expected Value Potential Cause Corrective Action
A. Sensor
Coil Installed or Uninstalled Multimeter 1 and 2 = R • Open or
Shorted Coil • Remove and replace sensor
B. Shields to
Case Installed or Uninstalled Multimeter 17 and
and case
ground
17 and case
ground
• Moisture in
terminal block
• Leaky electrode
• Process behind
liner
• Clean terminal
block
• Remove sensor
C. Coil Shield
to Coil Installed or Uninstalled Multimeter 1 and
2 and
(< 1nS)
(< 1nS) • Process behind
liner
• Leaky electrode
• Moisture in
terminal block
• Remove sensor
and dry
• Clean terminal
block
• Confirm with
sensor coil test
D. Electrode
Shield to
Electrode
Installed LCR (Set to
Resistance
and 120 Hz)
18 and 17 = R1
19 and 17 = R2
R1 and R2 should be stable
NO:
N5, E5, CD,
ED:
• Unstable R1 or
R2 values
confirm coated
electrode
• Shorted
electrode
• Electrode not in
contact with
process
• Empty Pipe
• Low conductivity
• Leaky electrode
• Remove coating
from sensor wall
• Use bulletnose
electrodes
• Repeat
measurement
• Pull sensor,
complete test in
Table6-6 and
Table 6-7 on
page6-10 out of
line.
2R18
0.2


R1R–2300
R1R21500
1nanosiemens 1
1gigaohm
----------------------------=
1nanosiemens 1
110
9ohm

-------------------------------=