10
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 recalibrated:
• 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 36).
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.
pH CALIBRATION
Pretreatment solutions are available to condition the
electrode and speed up the response time.
• The instrument automatically defaults to the
mV measurement mode if Hanna Instruments
P type ORP electrode is detected.
• Submerse the ORP electrode tip (3 cm (1¼”) into the sample. Allow
a few minutes for the reading to stabilize.
• The instrument displays the mV reading on the primary LCD.
• If the reading is out of range, the closest full‑scale value will be
displayed blinking on the primary LCD.
TAKING TEMPERATURE MEASUREMENTS
Connect the
HI7662
temperature probe and turn the
instrument on. Dip the temperature probe into the sample
and allow the reading on the secondary LCD to stabilize.