Emerson 381 instruction manual Troubleshooting Probable Cause Remedy

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MODEL 381pH/ORP

SECTION 3.0

 

MAINTENANCE

TABLE 3-1. Troubleshooting

 

Trouble

Probable Cause Remedy

 

 

 

 

 

 

 

Meter reads off scale.

Reference electrolyte depleted.

Replace reference electrolyte as

 

 

 

instructed in Section 3.2.2.

 

 

 

 

 

 

 

Defective preamplifier.

Check preamplifier as instructed in

 

 

 

Section 3.4 and replace

 

 

 

preamplifier if defective.

 

 

 

 

 

 

 

T.C. element shorted.

Check T.C. element as instructed in

 

 

 

Section 3.5, and replace body if

 

 

 

defective.

 

 

 

 

 

 

 

Electrode not in solution or sample

Make sure sensor is in solution or that

 

 

stream is not full.

sample stream is full (refer to Section

 

 

 

2.0 for installation details).

 

 

 

 

 

 

 

 

Open glass electrode.

Replace glass electrode.

 

 

 

 

 

 

 

Plugged liquid junction.

Replace liquid junction.

 

 

 

Recharge reference cell.

 

 

 

 

 

 

 

Reference element open-

Replace reference element.

 

 

no contact.

 

 

 

 

 

 

 

 

 

 

Meter reads between 3 and 6 pH

Electrode cracked.

Replace electrode.

 

regardless of actual pH of

 

 

 

 

 

solution or sample.

 

 

 

 

 

 

 

 

 

 

 

Meter indication swings widely

T.C. element shorted.

Check T.C. element as instructed in

 

in AUTO T.C. Mode.

 

Section 3.5 and replace body if

 

 

 

defective.

 

 

 

 

 

 

Span between buffers extremely

T.C. element open.

Check T.C. element as instructed in

 

short in AUTO T.C. mode.

 

Section 3.5 and replace body if

 

 

 

defective.

 

 

 

 

 

 

Sluggish or slow meter indication

Electrode coated.

Clean electrode as instructed in

 

for real changes in pH level.

 

Section 3.2.1.

 

 

 

 

 

 

 

Electrode defective.

Replace electrode.

 

 

 

 

 

 

Transmitter cannot be

Electrode coated or cracked.

Clean electrode as instructed in

 

standardized.

 

Section 3.2.1 and, if cracked,

 

 

 

replace electrode.

 

 

 

 

 

 

 

Reference chamber is contaminated

Replace gel solution as

 

 

 

instructed in Section 3.2.2.

 

 

 

 

 

 

 

Defective preamplifier.

Check preamplifier as instructed in

 

 

 

Section 3.4 and replace if

 

 

 

defective.

 

 

 

 

 

 

 

If trouble still persists, micro-junction

Replace micro-junction electrode.

 

 

electrode is defective.

 

 

 

 

 

 

 

 

 

Meter short spans.

Old glass electrode (greater than 1

Replace electrode.

 

 

year use).

 

 

 

 

 

 

 

 

 

 

Coated glass.

Clean with soft cloth and clean water.

 

 

 

 

 

 

 

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Contents PH/ORP Sensor Essential Instructions Model 381 pH/ORP Sensor About This Document Features and Applications Section Description and SpecificationsMaterials of Construction Sensor SpecificationsMeasuring Range pH Pressure Rating 790 kPa abs at 100C 100 psig at 212FExample Page Section Installation Model 381 Sensor Component Locator Diagram Section Submersion Installation Diagram Flow Through Installation Diagram Code 03 or Retro-Fit Kit Code 04 Flow Powered Cleaner, Model 40038105 40038103 40038116 START-UP and Calibration Model 381 ORPCalibration Section Maintenance Temperature C Millivolt Potential 268 264 260 Troubleshooting Probable Cause Remedy Temperature vs Resistance of Auto TemperatureElement Model 381 Spare Parts AccessoriesPage Section Ultrasonic Cleaner Operation 40038156 40037505 Section Return of Material NON Warranty RepairReturn of Materials Request Return of Material WarrantySpecifications subject to change without notice