Emerson Process Management 396PVP instruction manual Troubleshooting Without Advanced Diagnostics

MODEL 396P and 396PVP	SECTION 7.0
	TROUBLESHOOTING

7.2 TROUBLESHOOTING WITHOUT ADVANCED DIAGNOSTICS.

Table 7-2, below, lists common problems, causes and remedies typically encountered in process measurement.

TABLE 7-2. Troubleshooting without Advanced Diagnostics

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.

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