A130/131
I
24
Ion Measurement
The A series meter contains the 5 ion concentration measurement
methods, including the direct reading, known addition/subtraction and
sample addition/subtraction. If you selected mol/L or mmol/L as the
concentration unit, the incremental method will be disabled, the screen
will always show "Could not find the electrode slope", the meter must
be recalibrated in the concentration unit ppm or mg/L.
Direct Reading
1.1 Ensure that the meter is in the Ion (Direct Reading) mode.
1.2 Rinse the ion selective electrode with distilled water. Place the
electrode (and temperature probe) into the sample solution and
stir gently. Note, the ion sensitive membrane and liquid junction
must be completely immersed into the solution.
1.3 If the Auto-Read option in the setup menu is enabled, the meter
will automatically sense a stable reading and lock measurement,
the Hold icon appears on the screen. Press the key to resume
measuring.
If the option is disabled, the meter will continuously measure and
update the readings.
1.4 Wait for the measurement to stabilize and record the reading.
1.5 When all of the samples have been measured, rinse the electrode
with distilled water.
•
During the measurement process, never wipe the ion sensitive
membrane, blot dry with a lint-free tissue to remove waterdrops
on electrode.
•
To record the measurement at the predefined time intervals, refer
to the
Interval Readings
section on page 42.
Known Addition
2.1 Press the
Mode
key and the
key to select the
Ion (Known
Addition)
, press the
Enter
key to confirm.
2.2 Press the
key to select the electrode type (e.g., Ion 1). Press
the
Enter
key, the meter begins to measure the first mV value,
the icon E1 appears on the left of the screen.
2.3 Rinse the ion selective electrode with distilled water, place the
electrode (and temperature probe) into the sample solution. Wait
for the measurement to stabilize.
2.4 When the reading is stable, press the
Enter
key, the meter begins
to measure the second mV value, the icon E2 appears on the
screen.
2.5 Add a known volume of standard solution to the sample and wait
for the measurement to stabilize.
2.6 When the reading is stable, press the
Enter
key, the screen shows
a parameter list and waits for entering the sample volume,
standard volume and standard concentration (ppm or mg/L).
2.7 Press the
/
key to enter the value, press the
Enter
key to
confirm. When the setting is completed, the meter will calculate
and show the known addition result.
2.8 Press the
ESC
key to take a measurement again.
