Hanna Instruments Edge Instruction Manual page 66

Dissolved
Oxygen
Setup
66 Operational Guide
clockwise until the threads are fully engaged. Electrolyte will overflow.
7. Rinse outer body of the probe and inspect membrane for entrapped gas
bubbles. The cathode area should be free of bubbles.
8. Connect the DO probe to the edge™ meter and turn meter on
9. Allow probe conditioning function to occur.
Note: When not in use and during polarization, use the protective transparent
cap.
The conditioning message will be displayed for about 60 seconds while the
DO probe is conditioned. If the probe was conditioned and a new conditioning
is not necessary, press any key to enter measurement mode.
The probe is polarized with a fixed voltage of approximately 800 mV
between the cathode and anode. Probe polarization is essential for stable
measurements. With the probe properly polarized, oxygen is continually
consumed as it passes through gas permeable PTFE membrane.
If polarization is interrupted, the electrolyte solution continues to be
enriched with oxygen until it reaches an equilibrium with the surrounding
solution. Whenever measurements are taken with a non-polarized probe, the
measurement will be drifty and inaccurate. The measurement will jump when
the probe is moved.
During this process, the following message will be
displayed on the LCD, "DISSOLVED OXYGEN PROBE
CONDITIONING".