General WK2017SD User Manual page 14

7. To measure the DO content of a liquid, power on the meter and press the M button
until the display shows the term "do", indicating operation in DO measurement mode.
Then—after making sure that the optional oxygen probe you have obtained is full of
fresh electrolyte and has been recently calibrated—remove the protective cover from
the probe head and plug the probe into its dedicated socket on the top of the meter
(callout 1-14 of Fig. 1).
To make the DO content measurement, do the following:
1. Insert the probe at least 4 in. (10cm) into the liquid to be measured
2. Wait a few minutes for the instrument to automatically compensate for any difference
in temperature between the probe and the liquid
3. Read the DO content of the liquid in mg/L on the upper display and its temperature on
the lower display
4. Rinse the probe head with tap water after each measurement
5. Replace the probe head protection cover
Agitating a liquid reduces the effect of measurement errors caused
by oxygen diffusing into it from ambient air. At a minimum, this can
be done by shaking the probe while it is immersed. To minimize
measurement errors of this type, General recommends using a
magnetic agitator, especially in laboratory settings.
8. To measure the oxygen content of a volume of air, first make sure that the oxygen
probe to be used is full of fresh electrolyte and recently calibrated. Power on the meter
and press the M button until the display shows the term "do", indicating operation in
DO measurement mode. Then press the M button again to make the display read
"%O2" instead of "mg/L". Wait at least five minutes until the display reading stabilizes.
To return to "mg/L" readings, press the M button again.
Whenever the WK2017SD is in any measurement mode, you can turn off the backlight
(which is on by default) by briefly pressing (but not holding) the POWER/ESC button. To
reactivate the backlight, briefly press the button again.
Whenever the instrument is in any measurement mode, you also can check the current
date and time by briefly pressing the TIME button. Doing so causes both values to appear
briefly at the lower left of the display.
14
A DO measurement tip