47
Tr
OUBLESHOO
TING
G
UIDE
19. TROUBLESHOOTING GUIDE
SYMPTOMS
PROBLEM
SOLUTION
Slow response/excessive
drift.
Dirty pH or
reference electrode.
Soak the electrode tip
HI70640
solution
for 30 minutes and follow the cleaning
procedure. Refill reference electrode with
new fill solution.
Reading fluctuates up and
down (noise).
Clogged/dirty junction.
Low electrolyte level
(reference electrode).
Cable connection.
Clean the pH electrode. Refill reference
electrode with fresh fill solution. Check cable
connection to meter and verify protective
cap is off.
While in pH reading mode,
-2.00 or 16.00 pH is
displayed blinking.
Reading out of range. Check cable connection to meter and verify
protective cap is off. Check the quality of
the sample. Clean the electrodes. Refill with
fresh fill solution.
The pump calibration can’t
be performed.
Broken pump tubing.
Wrong or contaminated
pump calibration
solution.Broken pH
electrode
Verify tubing, valve, syringe are intact and
solution passes when pump is primed and
no air bubbles are present. Check the pump
calibration solution. Verify electrodes are
calibrated. Prepare another standard, prime
the pump and restart the calibration.
The meter does not accept
the pH buffer solution for
calibration.
Broken pH or reference
electrode.
Follow the electrode cleaning procedure. If
the error persists replace the electrode or
contact the vendor.
The temperature probe is
connected, but the meter
displays “MTC”.
Broken temperature
probe.
Replace temperature probe.
After a titration the
following is displayed
blinking: Low Range:
0.20 %I.a., 8.9 °SH,
20.0 °D or 22.2 °TH. High
Range: 0.1 %l.a., 4.4 °SH,
10 °D or 11.1 °TH.
Broken electrode.
Instrument not
calibrated. Wrong
sample. Concentration
out of range.
Check/clean the electrodes. Recalibrate the
instrument (pump and pH). Use care during
sample preparation. Check sample size and
permitted range.
