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3. Dissolved Oxygen Calibration
A “
∗
” in place of the decimal point indicates that the Dissolved Oxygen
readout is not calibrated, or a past calibration has failed. The “
∗
” will be
removed once an Air calibration has been successfully performed.
3.1 Calibration
1. Switch the
Aqua-D
on.
2. Select the desired % Saturation or ppM Mode (see section 2). Each
mode should be calibrated separately for optimum accuracy.
3. Plug the Dissolved Oxygen sensor into the sensor socket.
4. Ensure that temperature has already been calibrated (see section 4).
NOTE: If the decimal point in the temperature reading is replaced by
a “
∗
“, then the temperature readout is not calibrated.
5. Rinse the Dissolved Oxygen sensor in distilled water and blot dry.
6.
Zero Calibration
(a) Place the sensor into an oxygen-free solution. This solution may
be prepared by dissolving 2g of Sodium Sulphite in 100mL of
distilled water. A 50g bottle of Sodium Sulphite powder is
supplied with a new Dissolved Oxygen sensor for this purpose
(part number 123302).
(b) Allow the reading to stabilise at or near zero. This may take 2-3
minutes.
(c) Press and hold the
key for 2 seconds to calibrate.
(d) Discard the oxygen-free solution after use.
(e) A “
∗
“ will not be removed from the display after a Zero
Calibration.
7. Rinse the Dissolved Oxygen sensor in distilled water and blot dry.