LaMotte pH PLUS Direct Meter - Manual (Page 20)

5. ELECTRODE CARE AND MAINTENANCE
For best results, always keep the ISE capped dry and pH/ORP electrode bulb
wet. Store the pH/ORP glass bulb with pH electrode storage solution. pH
buffers are also suitable.
NEVER use deionized water for storage. Wash the
probes thoroughly with distilled water after each use. Because the ISE or pH
electrode is susceptible to contamination or dirt, clean it every 1 to 2 months
depending on extent and condition of use.
Clean the pH/ORP electrode using a mild detergent. Wipe the probe with soft
tissue paper. Avoid touching the glass membrane with your fingers. Wash the
electrode thoroughly in tap water and then in distilled water. Recalibrate the
meter after cleaning the electrode.
6. TROUBLESHOOTING
Problem Cause Solution
No display Batteries not in place a) Insert batteries.
b) Re-insert batteries with correct polarity.
“
LO” displays in
the LCD
Low battery Replace batteries with fresh ones.
Unstable
reading a) Electrode not deep
enough in sample
b) Dirty electrode
c) Broken electrode a) Place electrode deeper in sample.
b) Clean electrode and recalibrate.
c) Replace electrode.
“
Er1” display
Buffer value out of
tolerance Use new pH buffer solution and recalibrate.
“
Er2” display
Single point Perform at least 2 point calibration.
“
Er3” display
ISE slope not within
the specified tolerance Check ISE is in good working condition
.
“
Er4” display
Calibration points not
within 1 decade Ensure calibration points are at least 1
decade apart.
Not able to
calibrate a) Display freezes
b) Faulty electrode a) Release reading by pressing HOLD key.
b) Replace electrode.
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