MODEL 381pH/ORP  | SECTION 3.0 | 
  | MAINTENANCE  | 
TABLE 3-1.  Troubleshooting
  | Trouble  | Probable Cause Remedy | 
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Meter reads off scale.  | Reference electrolyte depleted.  | Replace reference electrolyte as  | 
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  | instructed in Section 3.2.2.  | 
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  | Defective preamplifier.  | Check preamplifier as instructed in  | 
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  | Section 3.4 and replace  | 
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  | preamplifier if defective.  | 
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  | T.C. element shorted.  | Check T.C. element as instructed in  | 
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  | Section 3.5, and replace body if  | 
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  | defective.  | 
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  | Electrode not in solution or sample  | Make sure sensor is in solution or that  | 
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  | stream is not full.  | sample stream is full (refer to Section  | 
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  | 2.0 for installation details).  | 
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  | Open glass electrode.  | Replace glass electrode.  | 
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  | Plugged liquid junction.  | Replace liquid junction.  | 
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  | Recharge reference cell.  | 
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  | Reference element open-  | Replace reference element.  | 
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  | no contact.  | 
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Meter reads between 3 and 6 pH  | Electrode cracked.  | Replace electrode.  | 
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regardless of actual pH of  | 
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solution or sample.  | 
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Meter indication swings widely  | T.C. element shorted.  | Check T.C. element as instructed in  | 
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in AUTO T.C. Mode.  | 
  | Section 3.5 and replace body if  | 
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  | defective.  | 
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Span between buffers extremely  | T.C. element open.  | Check T.C. element as instructed in  | 
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short in AUTO T.C. mode.  | 
  | Section 3.5 and replace body if  | 
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  | defective.  | 
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Sluggish or slow meter indication  | Electrode coated.  | Clean electrode as instructed in  | 
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for real changes in pH level.  | 
  | Section 3.2.1.  | 
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  | Electrode defective.  | Replace electrode.  | 
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Transmitter cannot be  | Electrode coated or cracked.  | Clean electrode as instructed in  | 
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standardized.  | 
  | Section 3.2.1 and, if cracked,  | 
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  | replace electrode.  | 
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  | Reference chamber is contaminated  | Replace gel solution as  | 
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  | instructed in Section 3.2.2.  | 
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  | Defective preamplifier.  | Check preamplifier as instructed in  | 
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  | Section 3.4 and replace if  | 
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  | defective.  | 
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  | If trouble still persists,   | Replace   | 
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  | electrode is defective.  | 
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Meter short spans.  | Old glass electrode (greater than 1  | Replace electrode.  | 
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  | year use).  | 
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  | Coated glass.  | Clean with soft cloth and clean water.  | 
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