CALIBRATION IN WATER SATURATED AIR
Note: Zero the sens
ion6
Dissolved Oxygen meter only when measuring dissolved oxygen levels less than 1
mg/L or 10% saturation. When measuring in this range, zero the meter prior to calibration.
1. Secure the probe cable to the calibration and storage chamber by wrapping cable through the
bottom of the chamber lid before filling with water.
2. 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.
3. 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.
4. Allow at least ten minutes for the atmosphere in the chamber to reach a steady state.
Note: Gently squeeze the lower chamber to force water-saturated air into the probe compartment to speed
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.
5. Press the
CAL
key located in the lower left corner of the keypad.
6. The main display will show the current value for the barometric pressure. If the meter has been
moved to a different elevation or if the barometric pressure has changed, enter the new value.
7. Press the
READ/ENTER
key. The display will show the current value for the altitude. Use the
keypad to enter the altitude of the meter.
Note: If the true barometric pressure has just been entered, the altitude has to be set to 0 meters (0 feet) or
inaccurate calibration may result.
8. When the altitude is correct in combination with the barometric pressure, press the
READ/ENTER
key. The current value for the sample salinity (
0/00
) will be shown.
a. Since this calibration is performed in water-saturated air, set the salinity to zero.
b. If necessary, use the keypad to enter a salinity value of
0 0/00
.
c.
Press the
READ/ENTER
key. The display will show
100%
.
d. Press the
READ/ENTER
key. The stabilizing icon will appear during the calibration.
9. When the calibration is complete, the meter will return to the read mode. Press the
EXIT
key
during the calibration sequence to back out of the calibration routine, one screen
one-at-a-time, without completing a calibration.
© Hach Company, 1999. All rights reserved. Printed in the U.S.A
ap/dk 5/99
