User Guide

9
DISSOLVED OXYGEN CALIBRATION
The calibration should be verified:
- After approximately 20 hours of use.
- Whenever the electrolyte or membrane is
changed and after cleaning the electrode.
- After excessive use in aggressive solu-
tions.
Accessories:
- 200 cc of HI 7040 solution
- 1 bottle of HI 7041 solution
Procedure for calibration at sea level:
• If you are starting from
the "OFF" position, switch
to "STB" and wait 30 min-
utes for complete polar-
ization of the probe be-
fore proceeding to the cali-
bration procedure.
ZERO CALIBRATION:
• Switch from "STB" posi-
tion to "O
2
" position.
• Remove the protective
cap and immerse the
probe in the HI 7040 zero
oxygen solution and wait
for approximately 5 min-
utes.
• The indications given by
the instrument must fall
to stabilization levels. If
the probe has not been
sufficiently polarized, the
readout will continue to
fluctuate.
OFF
O
2
STB °C
OFF
O
2
STB °C