Emerson Rosemount 389, Reference Manual

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5 Troubleshooting
Table 5-1: Troubleshooting
Trouble Probable Cause Remedy
Meter reads off scale (Display reads
overrange). Defective preamplifier. Replace preamplifier (for code 02
sensors). For code 01, replace sensor.
T.C. element shorted Check T.C. element as instructed in
Automatic temperature compensator
and replace sensor if defective.
Sensor not in process or sample
stream is low. Make sure sensor is in process with
sufficient sample stream (refer to
Install for installation details).
Open glass electrode. Replace sensor.
Reference element open - no contact. Replace sensor.
Display reads between 3 and 6 pH
regardless of actual pH of solution or
sample. Electrode cracked. Replace sensor.
Meter or display indication swings or
jumps widely in AUTO T.C. Mode. T.C. element shorted. Check T.Cl. element as instructed in
Automatic temperature compensator
and replace sensor if defective.
Span between buffers extremely short
in AUTO T.C. Mode. T.C. element shorted. Check T.Cl. element as instructed in
Automatic temperature compensator
and replace sensor if defective.
Sluggish or slow meter indication for
real changes in pH level. Electrode cracked. Clean sensor as instructed in Clean
electrode or Cleaning platinum
electrode . Replace sensor if cracked.
Electrode defective. Replace sensor.
Transmitter cannot be standardized. Electrode coated or cracked. Clean sensor as instructed in Clean
electrode or Cleaning platinum
electrode . Replace sensor if cracked.
Defective preamplifier Replace preamplifier.
Transmitter short spans between two
different buffer values. Old glass electrode or high
temperature exposure. Replace sensor.
Coated glass. Clean sensor as instructed in Clean
electrode or Cleaning platinum
electrode . Replace sensor if cracked.
Reference Manual Troubleshooting
00809-0100-3389 February 2019
Reference Manual 35