12
Calibration with Custom Standard
10.25 Make sure the unit is properly installed and electrode connected.
10.26 Press
and display will show
CAL
CAL
CAL
CAL
flashing on the left,
indicating it is in calibration mode to make an Offset point calibration.
10.27 Rinse the pH electrodes in distilled water then into the buffer solution
for Offset calibration or the slope buffer on continuity.
10.28 Main display will show the current measured value and the bottom
sub-display will show
2
2
2
2
.
00
00
00
00
or the previous value on continuity.
10.29 Press
to select the value nearest to the calibration solution.
The preset custom standards are
2
2
2
2
.
00
00
00
00
,
4
4
4
4
.
50
50
50
50
,
7
7
7
7
.
00
00
00
00
,
9
9
9
9
.
50
50
50
50
and
12
12
12
12
.
.50
.50
.50
.50
.
10.30 After selecting the nearest value, press
or
to adjust to
the exact value as the buffer solution at the current temperature being
used.
10.31 Press
to confirm and display will flash then revert to raw data.
10.32 Now you are ready to make Slope point calibration. Repeat step
10.27 to 10.31 in sequence. You can calibrate up to 4 slope points.
10.33
At least 2 calibration points (offset & slope) must be established in one
session of calibration. Otherwise, erroneous reading will result.
10.34 Only upon completing the entire session of calibration, press to
exit calibration mode and to begin measurement.
11. MAKING PH MEASUREMENT:
pH measurement with ATC (Automatic Temperature Compensation on sensor error)
11.1 This meter comes with an electrode with built in temperature sensor.
Plug in the BNC and mini-phone connector as in section 6 of page4.
The ATC sign will appear on the display.
11.2 Remove the electrode bottle carefully as in 5.4 of page3. Rinse probe
in distilled water before each test. Shake the electrode with a snap
motion, the way you would to a mercury thermometer and dip it into
the test solution, stir to remove any bubbles.
11.3 Once a reading is stabilized and the
READY
sign appear. You may
record the measurement.
Note on Measurements and Analysis:
Each type of liquid has its own pH value varies at different temperature.
ATC measurement only compensates for the pH sensor’s error, it does not
compensate for the pH variation due to temperature fluctuation in the liquid.
Therefore, each test should be made at the same temperature if possible or
recorded with temperature reading for a comprehensive analysis.
