7
Dissolved Oxygen Calibration in Water Saturated Air
1.
Plug in the DO probe at least 30 minutes before calibrating to
polarize the probe.
2.
Secure the calibration and storage chamber to the probe cable.
3.
Prepare the calibration and storage chamber by holding it under
water and squeezing it a couple of times to pull a small amount of
water into the lower chamber through the inlet. Alternately, open
the bottom of the chamber and insert a water-soaked sponge.
Note:
Avoid completely filling the lower chamber with water.
4.
Insert the DO probe into the calibration and storage chamber. The
tip of the probe must not be flooded with water or be holding a drop
of water on the membrane.
5.
Allow at least ten minutes for the atmosphere in the chamber to
reach a steady state.
Note:
Gently squeezing the lower chamber a couple of times to force water
saturated air into the probe chamber will speed up stabilization.
Note:
Keep the DO probe at a uniform temperature. When holding the probe,
do not touch the metallic button on the side of the probe. The button is a
thermistor that senses temperature. An inaccurate calibration will result if
the temperature of the thermistor is different from the probe membrane.
6.
Press the
DO
key to put the meter in DO reading mode.
7.
Press the
CAL
key located in the lower left corner of the keypad.
8.
The display will show
100%
. Press the
ENTER
key. The stabilizing
icon will appear while the meter completes the calibration.
9.
When the calibration is complete, the meter will return to reading
mode. Press the
EXIT
key during the calibration sequence to back
out of the calibration routine, one screen at a time, without
completing a calibration.
