LAQUAtwin series (K
+
) Operation
3
CODE: GZ0000460287
Note
If a measured value is out of the specified
measurement range, "Or" is displayed for
upper range and "Ur" is displayed for under
range.
When you have a problem with the calibration
or measurement, refer to frequently asked
questions.
Sampling sheet
For a minute sample
Note
Note that reaction between sample and sam-
pling sheet B may affect the measured value.
Handle sampling sheet B with tweezers to
minimize possible contamination.
Be sure to close the light shield cover during
measurement to minimize possible sample
evaporation.
For a sample containing tiny particles
If tiny particles are contained in a sample, such
as an extract from soil, the particles influence
measurement results. Use the sampling sheet
holder cover and sampling sheet B sold sepa-
rately to counteract the influence.
Note
The sampling sheet holder cover does not shield
the sensor from light, which affects the sensor.
When using the sampling sheet holder cover,
shield the flat sensor from light with an alterna-
tive.
1. Replace the light shield cover with the sam-
pling sheet holder cover.
2. Put a piece of sampling sheet B on the flat
sensor and close the sampling sheet
holder cover.
3. Put 4 or 5 drops of sample on the sampling
sheet B.
Measurement display change
The display mode switches among concentration
(the unit depends the setting), temperature, and
voltage by pressing the MEAS switch in the AS
mode.
Maintenance
Appendix
Interfering ions
Selectivity coefficient is a concentration ratio of
the interfering ion against the target ion, which
affects the target ion measurement value. For
example, selectivity coefficient of interfering ion
against target ion is 1
10
-2
, which means for the
same concentration of interfering ion and target
ion coexisting in a sample, the target measure-
ment shows approximately 1
10
-2
(1%) higher
result.
Try to use the provided
sampling sheet B for a
minute sample.
Using this sheet, the
entire flat sensor can be
covered with only 50
L
to 100
L sample.
Storage
1. Clean the sensor with tap water.
2. Dab gently with soft tissue or cloth to
remove moisture on the sensor and meter.
Note
Especially be sure to treat the flat sensor gently
to prevent damaging it.
3. Close the light shield cover and the slide
cap before storing the meter.
Temperature sensor adjustment
To perform accurate measurement with correc-
tion for temperature effects, follow the steps
below. Normally this is not necessary.
1. Ready a reference thermometer, and allow
the meter and reference thermometer to
reach to room temperature.
Sampling sheet
holder cover (Part No.: 3200459736)
Light shield cover
Sampling sheet B
(Part No.: 3200053858)
2. Set the display mode to temperature refer-
ring to "
Measurement display change"
(page 3).
3. Press the CAL switch.
The meter displays the setting screen for
target temperature.
4. Press the MEAS switch to adjust the dis-
played temperature on the meter to match
the temperature indicated by the reference
thermometer.
Pressing the MEAS switch increases the
displayed temperature. After the displayed
temperature reaches 40°C, it returns to 5°C.
5. Press the CAL switch again to apply the
displayed value to the adjustment.
The adjustment starts. The adjusted value
blinks with
and
displayed.
After the adjustment is complete, the adjusted
value stops blinking with MEAS and
displayed.
If Er4 (error display) appears, the adjustment
has failed. Retry the above steps increasing
the time spent on the step 1.
If the adjustment repeatedly fails, the sensor
may have deteriorated. Replace the sensor
with new one.
Initializing calibration data
Initialize calibration in the following cases.
To delete the calibration data
If the number of points for the last calibration is
uncertain.
After the sensor is replaced.
1. Press and hold the CAL and ON/OFF
switches for over 3 seconds when the
meter is switched OFF to Initialize calibra-
tion.
After a moment of all segment indication, the
software version is displayed.
And then, the display
changes as shown right.
2. Press the CAL switch.
All calibration data is reset.
When the initialization of
calibration data is complete,
End appears.
The meter automatically switches OFF.
Initializing the settings
All setup choices are erased. The meter is reset
to the factory default values.
1. Press and hold the MEAS, CAL and ON/OFF
switches for over 3 seconds when the
meter is switched OFF to enter the initial-
ization.
After a moment of all segment indication, the
software version is displayed.
And then, the display
changes as shown right.
2. Press the CAL switch.
All calibration data is reset.
When the initialization of
settings is complete, End
appears.
The meter automatically switches OFF.
Target
Potassium ion (K
+
)
Interfering ions and
selectivity coefficients
Rb
+
: 1
10
-1
(at 10
-3
mol/L K
+
)
pH range
2 pH to 9 pH
(at 10
-3
mol/L K
+
)
