Hanna Instruments wm 8910 User Manual

2 7

2 6

Make sure a combination pH electrode is connected to the BNC socket
and the meter is plugged to the mains.
Turn the switch to the "MEASURE" position.
The calibration should be ideally performed at
the temperature of the liquid that is being
controlled.
Use a ChecktempC (or an accurate thermometer) as reference for a
temperature compensated calibration.

OFFSET ADJUSTMENT:

• Remove the protective cap from the elec-

trode, rinse it with some pH 7.01 solution
(HI 7007), then dip it in pH 7.01 buffer.

Note: The electrode should be submerged approximately 4 cm (1½")

into the solution. The thermometer should be located close to
the pH electrode.

For WM 8910 and WM 8911 only:
• Short the MTC and the middle terminals and adjust the "°C"

knob to the temperature of the solution (e.g. 25°C).

• Stir the electrode and wait about one

minute before adjusting the "OFFSET"
or the "pH7" trimmer to display pH 7.01
on the LCD if the temperature of the
buffer solution is at 25°C (77°F).

• If the temperature of the buffer solu-

tion is not 25°C (77°F), refer to the
chart on page 37 for the appropriate
buffer value at a given temperature.

4 cm

(1½

")

HI 7007

°C

When the meter is in pH
dosage mode and the ter-
minals are activated, the
DOSE LED will be lit
(for     WM 8912, WM 8913

and WM 8923 only).

Likewise for the DOSE LED
of the  ORP controller
WM 8912.

Similarly, DOSE LED of
WM 8913 and WM 8923
will be lit when conductiv-
ity terminals are activated.

Note: When both the LEDs are lit up simultaneously, the pH dosage

is given priority over ORP/conductivity dosage.