eutech-instruments calcium epoxy Manuel D’Utilisation
Instruction Manual
Calcium Electrode
17
TROUBLESHOOTING HINTS
Symptom
Symptom
Possible Causes
Next Step
Out of Range
defective meter
check meter with shorting strap
Reading
(see meter instruction manual)
defective electrode
check electrode operation
electrodes not
unplug electrodes and reset
plugged in properly
reference electrode
be sure reference electrode is filled
not filled
air bubbles on
remove bubbles by
membrane
re-dipping electrode
electrodes not
put electrodes in solution
in solution
Noisy or Unstable
defective meter
check meter with
Readings (readings
shorting strap
continuously or
randomly changing air bubble on
randomly changing air bubble on
remove bubble by
membrane
re-dipping electrode
meter or stirrer
ground meter or stirrer
not grounded
outer filling solution
fill electrode to level just
too low
below fill hole
defective electrode
replace electrode
electrode exposed to
soak electrode in calcium standard
interferences
"Incorrect
incorrect scaling
plot millivolts on the linear
Answer"
of semi-log paper
axis. On the log axis, be sure
(but calibration
concentration numbers within
curve is good)
each decade are increasing
increasing concentration
incorrect sign
be sure to note sign of
millivolt number correctly
incorrect standards
prepare fresh standards
wrong units used
apply correct conversion factor:
1.0x10
-3
M = 40 ppm Ca
+2
=
100 ppm as CaCO
3
sample carryover
rinse electrodes thoroughly