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7.2 TROUBLESHOOTING WITHOUT ADVANCED DIAGNOSTICS.
Table 7-2, below, lists common problems, causes and remedies typically encountered in process measurement.
Problem
Probable Cause
Remedy
Meter reads off scale. (Display
Defective preamplifier
Replace preamplifier (for code 02
reads overrange).
sensors). For code 01, replace sensor.
T.C. element shorted
Check T.C. element as instructed
in Section 6.1 and
replace sensor if defective.
Sensor not in process. Sample
Make sure sensor is in process with
stream is low or air bubbles are
sufficient sample stream (refer to
present.
Section 2.0 for installation details).
Open glass electrode
Replace sensor.
Reference element open - no contact
Replace sensor.
Display reads between 3 and 6 pH
Electrode cracked
Replace sensor.
regardless of actual pH of solution
or sample.
Meter or display indication swings
T.C. element shorted
Check T.C. element as instructed
or jumps widely in AUTO T.C. Mode.
in Section 6.1 and replace
sensor if defective.
Span between buffers extremely
T.C. element open
Check T.C. element as instructed
short in AUTO T.C. Mode.
in Section 6.1 and replace sensor
if defective.
Sluggish or slow meter indication
Electrode coated
Clean sensor as instructed in
for real changes in pH level.
Sections 6.2 or Section 6.3.2.
Replace sensor if cracked.
Electrode defective
Replace sensor.
Transmitter cannot be standardized.
Electrode coated or cracked
Clean Sensor as instructed in
Sections 6.2 or Section 6.3.2
Replace sensor if cracked.
Defective preamplifier
Replace preamplifier.
Transmitter short spans between
Aged glass electrode or high
Replace sensor.
two different buffer values.
temperature exposure
Electrode coated
Clean Sensor as instructed in
Section 6.2 or Section 6.3.2.
Replace sensor if cracked.
Air bubbles trapped in sensor end
Shake the sensor in solution. See
between glass bulb and sensor body Section 2.0 for mounting guidelines.
TABLE 7-2. Troubleshooting without Advanced Diagnostics
MODEL 396P and 396PVP
SECTION 7.0
TROUBLESHOOTING
