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Page 7
3. pH Calibration
A “
∗
” in place of the decimal point indicates that the pH readout is not
calibrated, or a past calibration has failed. The “
∗
” will be removed once
a full two-point pH calibration has been successfully performed.
3.1 Calibration
1. Switch the
Aqua-pH
on.
2. Select pH Mode (see section 2).
3. Plug the pH sensor into the BNC socket (this is the metal socket). For
automatic temperature compensation, plug the Temperature sensor
into the Temperature socket (this is the 6-pin plastic socket). If the
Temperature sensor is not connected, then the
Aqua-pH
will use
manual temperature compensation.
4. Ensure that temperature has already been calibrated, or manually set
(see sections 5.1 and 5.4). NOTE: If the decimal point in the
temperature reading is replaced by a “
∗
“, then the temperature
readout is not calibrated.
5. Remove the wetting cap from the pH sensor.
6. Rinse the pH and Temperature sensors in distilled water and blot
them dry.
7. Ensure that you are using the buffers which have been selected for
automatic buffer recognition. See section 6 for a detailed explanation.
8. Place both sensors into a small sample of pH6.88 (or pH7.00) buffer,
so that the bulb and reference junction are both covered. See the
diagram over the page.