21
I
A130/131
Temperature Compensation
Due to the temperature difference between the standard and sample
solutions will cause approximately 2% measurement error for every
degree centigrade of temperature change, we recommend to enable
the temperature compensation during the calibration and
measurement.
Automatic Temperature Compensation
Connect the temperature probe to meter (refer to the
Connecting the
Temperature Probe
section on page 8).
The ATC icon appears on the screen, the meter is now switched to the
automatic temperature compensation mode.
Manual Temperature Compensation
If the meter does not detect a temperature probe, the degrees Celsius
icon (° C) will show on the screen indicating the meter is switched to
the manual temperature compensation mode. To set the temperature
value follow the steps below.
1. Press and hold the
° C
key to enter the temperature setting.
2. Press the
/
key to modify the temperature value.
3. Press the
Enter
key to save.
Press and hold the
/
key will make the value change faster.
Ion Calibration
The A series meter allows 2 to 5 points ion calibration, acceptable
calibration points include the following options.
Measurement Unit
Calibration Points
ppm, mg/L
0.001, 0.01, 0.1, 1, 10, 100, 1000, 10000
mol/L, mmol/L
0.001, 0.01, 0.1
Before beginning the calibration, ensure that the ionic valency option
in the setup menu matches connected electrode. All of the standards
and samples should be at the same temperature and calibration
points cover the anticipated range of the samples.
For the low concentration or sample contains the interference ions,
we recommend to add the ionic strength adjuster (ISA) to all of the
standards and samples. A typical addition would be 2 ml ISA to 100 ml
of standard and sample.
For the low level sodium determination (<
1 ppm), make sure to use the
laboratory plastic beaker as a container.
Stir the standards and samples at a uniform rate that will help you get
most accurate readings.
Ion Concentration Calibration
1. Ensure that the meter is in the Ion (Direct Reading) mode.
2. Press the
Cal
key, the screen shows "Calibration Point 100 ppm".
3. If necessary, press the
/
key to select first calibration
point, the meter will automatically perform the calibration from
the low to high concentrations.
4. Rinse the ion selective electrode with distilled water, then rinse
with a small amount of standard solution. Place the electrode
(and temperature probe) into the standard solution, stir gently to
create a homogeneous solution.