Filter
Top Products
5
MODEL 404 WIRING
TROUBLESHOOTING
PROBLEM PROBABLE CAUSE SOLUTION
Off-scale reading Wiring is wrong. Verify wiring.
Temperature element is open or shorted. Check temperature element for open or
short circuits. See Figure 9.
Sensor is not in process stream. Be sure sensor is completely submerged in
process stream.
Variopol cable is not properly seated. Loosen connector and reseat.
Sensor has failed. Perform isolation checks. See Figure 10.
Noisy reading Sensor is improperly installed in process Be sure sensor is completely submerged
stream. in process stream.
Variopol cable is not properly seated. Loosen connector and reseat.
Reading seems wrong (lower Bubbles trapped in sensor. Be sure sensor is properly oriented in
or higher than expected) pipe or flow cell. See Figure 1.
Apply back pressure to flow cell.
Wrong temperature correction algorithm. Check that temperature correction is
appropriate for the sample. See analyzer
manual for more information.
Wrong cell constant. Verify that the correct cell constant has
been entered in the analyzer and that the
cell constant is appropriate for the conductivity
of the sample. See analyzer manual.
Sluggish response Electrodes are fouled. Clean electrodes.
Sensor is sampling a dead area. Move sample line to a location more
representative of the process liquid.
FIGURE 9. Checking Temperature Element
Disconnect leads and measure resistance shown. The meas-
ured resistance should be close to the value in the table.
FIGURE 10. Checking Continuity and Leakage
Disconnect electrode leads and measure resistance and
continuity as shown. Sensor must be dry when checking
resistance between electrode leads.