Section 5: Troubleshooting - Emerson Rosemount 385 Reference Manual

Reference Manual
00809-0100-3385

Section 5: Troubleshooting

5.1 Troubleshooting
Table 5-1: Troubleshooting
Trouble
Meter reads off scale. (Display
reads overrange.)
Display reads between 3 and 6
pH regardless of actual pH of
solution or sample.
Meter or display indication
swings or jumps widely in
AUTO T.C. Mode.
Span between buffers
extremely short in AUTO T.C.
Mode.
Sluggish or slow meter
indication for real changes in
pH level.
Transmitter cannot be
standardized.
Transmitter short spans
between two different buffer
values.
Note: For any repair or warranty inquiries please contact our Customer Care group.
Troubleshooting
Probable Cause
Defective preamplifier.
T.C. element shorted.
Electrode not in solution or sample.
or stream is not full.
Open glass electrode.
Electrode cracked.
T.C. element shorted.
T.C. element open.
Electrode coated.
Electrode defective.
Electrode coated or cracked.
Defective preamplifier.
Old glass electrode (greater than 1 year old).
Coated glass.
Troubleshooting
Remedy
Check preamplifier as instructed in Section
4.2.3 and replace preamplifier if defective.
Check T.C. element as instructed in Section
4.2.2 and replace sensor tube if defective.
Make sure sensor is in solution that sample
stream is full (see Section 2.0 for installation)
Replace sensor tube.
Replace sensor tube.
Check T.C. element as instructed in Section
4.2.2 and replace sensor tube if defective.
Check T.C. element as instructed in Section
4.2.2 and replace sensor tube if defective.
Clean sensor as instructed in Sections 4.2.1 or
4.4.2.
Replace sensor tube.
Clean sensor as instructed in Sections 4.2.1 or
4.4.2 and, if cracked,replace sensor tube.
Check preamplifier as instructed in Section
4.2.3 and replace preamplifier if defective.
Replace sensor tube.
Clean Sensor as instructed in Sections 4.2.1 or
4.4.2.
February 2019
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