MODEL 396R pH/ORP

SECTION 7.0

 

DIAGNOSTICS AND TROUBLESHOOTING

7.2TROUBLESHOOTING WITHOUT DIAGNOSTICS. Table 7-2 lists common problems, causes and remedies typically encountered in process measurement.

TABLE 7-2. Troubleshooting without 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 6.5 and

 

 

 

replace sensor if defective.

 

 

 

 

 

Sensor not in process or sample

 

Make sure sensor is in process with

 

stream is low.

 

sufficient sample stream (refer to

 

 

 

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 6.5 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 6.5 and replace sensor

 

 

 

if defective.

 

 

 

 

Sluggish or slow meter indication

Electrode coated.

 

Clean sensor as instructed in

for real changes in pH level.

 

 

Sections 6.3 or 6.4. Replace

 

 

 

sensor if cracked.

 

 

 

 

 

Electrode defective.

 

Replace sensor.

 

 

 

 

Transmitter cannot be standardized.

Electrode coated or cracked.

 

Clean Sensor as instructed in

 

 

 

Sections 6.3 or 6.4 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

 

 

 

Sections 6.3 or 6.4. Replace

 

 

 

sensor if cracked.

 

 

 

 

37

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Image 41
Emerson 396RVP instruction manual Sensors. For code 01, replace sensor