Hanna Instruments HI 8711 - Manual (Page 28)

28
Make sure that the instrument is in measurement
mode (MEASURE LED is on) before proceeding
with calibration.
Measure the temperature of the calibration
buffer with a reference thermometer.
Remove the protective cap from the electrode.
Rinse the pH electrode and the reference
thermometer in pH 7.01 rinsing solution and
then immerse them in pH 7.01 buffer solution
(HI 7007).
Note: The electrode should be submerged at
least 4 cm (1½") into the solution. The
thermometer should be located as close
as possible to the pH electrode.
Shake briefly and wait one minute before adjusting the OFFSET
trimmer to display the buffer solution value, i.e. "pH 7.01" at 25°C
(77°F).
If the buffer solution temperature is different from 25°C (77°F), refer
to the "pH vs. temperature" chart on page 30 for the appropriate pH
value at the noted temperature.
Two DOSAGE MODE switches are designed for HI8711, one for ACID
and the other for ALK. channels. If for any reason one of them is in
OFF position the corresponding dosing relay is deactivated. The alarm
relay will be activated only in accordance with the other channel.
The ALARM LED will work as in AUTO mode.
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