Manual

11
ZERO CALIBRATION
• Submerse the probe into HI 7040 zero oxygen
solution and stir gently for 2-3 minutes.
• Press CAL. The “~” and “ ” tags will blink on the
LCD until the reading is stable.
• When the reading is stable, “CFM” starts blinking.
Press CFM to confirm the “0.0%” DO calibration.
• If the reading is within the limits (±15% f.s.), the
meter stores the value (and adjusts the slope point).
• Press CAL. The instrument will return to measurement
mode and will memorize the zero calibration data.
For a two-point calibration do not press CAL and
follow the procedure below.
SLOPE CALIBRATION
It is suggested to perform the slope calibration in air.
• Rinse the probe in clean water to remove any residual
zero oxygen solution.
Note: If you did not perform the zero calibration procedure, press CAL
and then the ARROW keys to select the 100% DO calibration
point.
• Dry the probe tip and allow a few seconds for the LCD reading to
stabilize. The “
~~
~~
~” and “ ” tags will blink until the reading is
stable.
• When the reading is stable, “CFM” tag starts blinking. Press CFM to
confirm the “100.0%” DO calibration.
• If the reading is within the limits (±15% f.s.), the
meter stores the value (and adjusts the slope point).
OR