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LAQUAtwin series (Na

+

) Operation

4

CODE: GZ0000460286

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?

Acids influence measurement 
results. Measure within the range 
from 3 pH to 9 pH. Also, high-level 
monovalent cations, such as K

+

may cause measurement errors.
Refer to " 

 Interfering ions" (page 

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 sodium chloride in ion-
exchanged water to the specified 
concentration.

Question

Answer

Summary of Contents for LAQUAtwin-Na-11

Page 1: ... The closeness of agreement between a mea sured value and an actual value of standard solu tion after two point calibration using 150 ppm and 2000 ppm standard solutions The standard solution used for the later cali bration was measured after two point calibra tion at 150 ppm and 2000 ppm The calibration and measurement are per formed at the same temperature The error of standard solutions and rou...

Page 2: ...asurement mode automatically 5 Open the light shield cover and remove the standard solution Then remove moisture on the sensor by gently dabbing with a soft tissue This completes the 1st point calibration 6 To perform 2nd point calibration repeat steps 2 to 5 Calibration error If blinks and Er4 error dis play appears the calibration has failed Perform electrode conditioning Check that the correct ...

Page 3: ...perature 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...

Page 4: ...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 i...

Page 5: ... concen tration is changed the calibration data are initialized 2nd calibration point setting The concentration of the 2nd calibration point can be set In calibration point setting pressing the MEAS switch increases the displayed value After the displayed value reaches 9800 it returns to 3 All segment indication 2 s Software ver indication 1 s ON OFF switch MEAS switch CAL switch ppm default mg L ...

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