Hanna Instruments HI 2222 User Manual

Page 9

Calibrate the instrument frequently, especially if high accuracy is
required. For best results and constant display of electrode condition
and electrode response on the bar graph gauges, daily calibration is
recommended.
The instrument should be re-calibrated:
• Whenever the pH electrode is replaced.
• At least once a day.
• After testing aggressive chemicals.
• If high accuracy is required.
• If “CAL DUE” message is displayed during measurement.
Every time you calibrate the instrument use fresh buffers and perform an
electrode cleaning procedure (see page 33).
PREPARATION

PREPARATION

PREPARATION
Pour small quantities of the buffer solutions into clean beakers. If possible,
use plastic or glass beakers to minimize any EMC interferences.
For accurate calibration and to minimize cross-contamination, use two
beakers for each buffer solution. One for rinsing the electrode and one for
calibration.

PROCEDURE

PROCEDURE
A two-point calibration is recommended, however a one-point calibration
will be permitted. Calibration can be performed using the seven
memorized buffers:
• pH 1.68, 3.00, 6.86, 7.01, 9.18, 10.01 and 12.45.

pppppH CALIBRATION

H CALIBRATION