LAQUAtwin series (Ca
2+
) Operation
4
CODE: GZ0000460289
ment shows approximately 1
10
-2
(1%) higher
result.
Frequently asked questions
Question
Answer
How can I
check the
sensor's con-
dition?
Perform 2-point calibration. If cali-
bration error occurs, the sensor has
deteriorated. Replace the sensor.
Can I mea-
sure high or
low tempera-
ture sam-
ples?
This meter cannot measure a sam-
ple with temperatures outside the
meter's operating temperature range
(5
C to 40
C).
The difference between the sample
temperature and ambient tempera-
ture increases the measurement
error. Perform measurement after
the sample reaches the ambient
temperature.
The mea-
sured value
does not
change after
changing the
sample.
If
lights steadily in AH mode, the
measured value is locked.
Press the MEAS switch to unlock the
value.
If the value does not change after
unlocking, the sensor may be dam-
aged. Replace the sensor.
“Or” or “Ur”
blinks in
value mea-
surement.
The measured value may be out of
the specified measurement range.
Measure a standard solution to
check, and if “Or” or “Ur” still blinks,
replace the sensor.
blinks
during mea-
surement.
The measured temperature is not
within the specified operating tem-
perature (5
C to 40
C).
If the ambient temperature is within
the specified range and
blinks,
replace the sensor.
The meter
does not
power ON.
Check that the batteries are inserted
properly. If the battery voltage is low,
replace them both with new ones at
the same time.
Er4 is dis-
played during
the calibra-
tion
Please note that if you press the
CAL switch in mV or temperature
display mode, Er4 is displayed. This
is because there is no calibration
facility available for these modes.
Er1 is dis-
played soon
power ON.
The internal IC in the meter may be
defective. Perform meter initializa-
tion.
If Er1 is still displayed after the initial-
ization, the internal IC in the meter is
defective. Replace the meter with a
new one (the meter cannot be
repaired).
Er2 is dis-
played right
after power
ON.
The internal IC in the meter is defec-
tive. Replace the meter with a new
one (the meter cannot be repaired).
Er3 is dis-
played right
after power
ON.
The internal IC in the meter is defec-
tive. Replace the meter with a new
one (the meter cannot be repaired).
What factors
interfere
measure-
ment?
Strong acids and strong alkalis influ-
ence measurement results.
Measure within the range from 4 pH
to 12 pH.
Also, high-level divalent cations,
such as Fe
2+
or Zn
2+
, may cause
measurement errors.
Refer to "
3) for details.
Are there any
helpful tips or
precautions
to be aware
for measure-
ment?
When the sample amount is enough,
washing the sensor twice or so with
the sample allows more accurate
measurement.
Residue between the light shield
cover and flat sensor prevents accu-
rate measurement. Before measure-
ment of the next sample, wash the
sensor with tap water and remove
moisture.
Question
Answer
Can I pre-
pare stan-
dard
solutions
myself?
You can prepare standard solutions
by dissolving calcium chloride in ion-
exchanged water to the specified
concentration.
For the provided standard solution,
potassium chloride is added as the
supporting electrolyte salt until 0.1
mol/L is reached.
Question
Answer
