YSI 63 - Manual (Page 11)

For best results:
•
Calibrate as close as possible to the sample temperature.
•
After storage in pH 4 buffer/KCl solution, place the pH sensor in pH 7 (6.86) buffer and
allow to acclimate before calibrating (5 to 10 minutes).
•
Always give the pH and temperature sensors enough time to equilibrate with the
temperature of the buffer.
Temperature sensor
pH sensor (covered by sensor guard)
Figure 5
4. To enter the calibration menu, use two fingers to press and release both the UP ARROW
and DOWN ARROW keys at the same time. The Model 63 display will show CAL at the
bottom, STAND will be flashing and the pH reading will show 7.00 (the buffer to be used to
adjust the offset).
7.00
pH
STAND CAL
24.8
°C
First buffer value.
Used to adjust the offset.
Flashing
NOTE: If you will be calibrating with pH buffers of 6.86, 4.01 and 9.18 (instead of 7, 4 and 10),
press both the UP ARROW and DOWN ARROW keys again. The display will change to
6.86.
NOTE: The Model 63 automatically accounts for the fact that the true pH of the buffers changes
with temperature, therefore, the pH values displayed during calibration will vary with
temperature. For example, pH 7 buffer at 20°C (rather than 25°C) has an actual pH of 7.02
and this number (rather than 7.00) will appear on the display when the probe is placed in the
solution. See Appendix C - pH Buffer Values.
7