Electro-Chemical Devices (ECD) L20 - Manual (Page 8)

4. Rinse the pH and ATC/Temp probe in distilled water and
immerse them in the second buffer solution (either
4.00/4.01 or 9.18/10.01). Allow temperature reading to
stabilize, then press “Slope” key to calibrate. The “WAIT”
icon will flash until the unit detects a stable reading. Once
the unit calibrates the second point, the “SLOPE” icon will
flash. The unit is ready to be sloped at the third buffer.
[Note: At this moment, press the “Mode” key, to exit the
calibration mode. Dual point calibration is complete.]
5. Rinse the pH and ATC/Temp probe in distilled water and
immerse them in the third buffer solution (either
9.18/10.01 or 4.00/4.01). Allow temperature reading to
stabilize, then press “Slope” key to calibrate. The “WAIT”
icon will flash until the unit detects a stable reading. Once
the unit calibrates the third point and the unit will
automatically exit the calibration mode. The three point
calibration is complete.
6. The unit calculates and compensates for the pH electrode
slope deviation corresponding to the values of the three
calibration buffers. After calibration, press and hold
“Mea./Eff.” key for about 5 seconds to display the new
electrode efficiency.
Calibration with manual temperature compensation in
the pH-AUTOLOCK mode
1. Turn the unit on. Press “Clear” key for 2 seconds, all LCD
elements will light up. The meter clears all calibration
values stored in internal memory.
2. Connect the pH electrode to the BNC connector of the
unit, “MAN” icon will light up. “pH” icon and “AUTO” icon
light up. The buffer set icon will flash.
3. Rinse the pH probes in distilled water and immerse it in
the first buffer solution (either 7.00 or 6.86). Adjust the
temperature reading to that of the first buffer using the up
or down keys (0.0 to 60.0℃) before pressing the “Stand”
key. Then press and hold the “Stand” key for 5 seconds to
calibrate. The “WAIT” icon will flash until the unit detects a
stable reading. Once the unit calibrates the first point, the
selected buffer remains lit up while the remaining two
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