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
CALCAL
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
22
2.00
0000
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
22
2.00
0000
00, 4
44
4.50
5050
50, 7
77
7.00
0000
00, 9
99
9.50
5050
50 and 12
1212
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 temp