Users Manual

29
CALIBRATION
Two Points Automatic Calibration at 0% Saturation (0 mg/L) and 100% Saturation (8.26 mg/L)
Note: If performing the two point calibration, the 0 point must be done first.
Submerge the probe into HI7040 zero oxygen solution and stir gently for 2-3 minutes.
Press CAL. The calibration menu will be displayed. Wait for the temperature and probe values to
become stable.
Press DO to select the DO calibration. The meter will automatically recognize the 0 standard.
The DO calibration screen will be displayed and the standard 0% saturation (or 0 mg/L, depending
on the currently selected measuring unit), will be automatically selected.
When the reading is stable within the acceptable range, the CFM functional key is displayed.
Press CFM to confirm the calibration point.
Remove probe from the standard and rinse it off completely in running water to remove all traces of
zero standard. Blot any water off the cap with a lint free tissue.
Suspend the probe into the water saturated air container and wait for the probe and sample to reach
thermal equilibrium.
The meter will automatically recognize the 100% saturated standard (or equivalent mg/L).
The standard 100% saturation (or 8.26 mg/L), will be automatically displayed.
When the reading is stable within the acceptable range, the CFM functional key is displayed.
Press CFM to confirm the calibration point. The meter will return to the measurement screen and the
probe will store the calibration data.