Go to
www.milwaukeetesters.com there is a manuals section that includes the SMS122.
from the site.
CALIBRATION PROCEDURE:
• Remove the protective cap from the electrode.
• Immerse the electrode tip into a new sachet of pH 7
calibration solution and allow the reading to stabilize.
• Adjust the OFFSET calibration trimmer (on the front)
to display "7.0 pH".
• Open a new sachet of pH 4 calibration solution and
use a small quantity to rinse the electrode.
• Immerse the electrode tip into the pH 4 sachet and
allow the reading to stabilize.
• Adjust the SLOPE calibration trimmer (on the rear)
to display "4.0 pH".
• The calibration is now complete and the meter is
ready to take measurements.
• It is suggested to recalibrate the meter at least
once a month, after a prolonged stocking time
and after pH-electrode replacement.
I also got this card in mine that says to use one point calibration.
-Mike