2. Zero Calibration:
First prepare a container of oxygen depleted water. One of the
chemicals that are effective in depleting the 0
2
in water is Sodium Sulfite (NaSO
2
). Use
one gram/quart of water, mix well and allow up to one hour to deplete the oxygen before
using.
Warning: let probe sit in prepared water for (30) minutes or longer in order
to allow the sensor to equilibrate prior to adjustment.
It may take as long as (45)
minutes or more to go from air to zero level, so make sure a stable zero level has been
obtained before adjusting the instrument. The probe can be gently moved up or down
to speed the process, however no flow is required to calibrate or operate the instrument.
When ready, press the red read button on the faceplate of the unit. This will allow (2)
minutes to adjust the instrument using the zero calibrate set point. After adjustment, the
unit will be calibrated to zero (0). Changing the probe from zero to air can contaminate
the calibration solution so be sure to rinse the probe clean before each step.
3. Air Calibration:
Air calibration is an easy and reliable method to use to calibrate the
unit. This technique must be performed out of direct light. If the probe is mounted in a
float device for aquaculture or mounted in a pipe for wastewater, pull the probe out of
the water and wipe off the sensor end. After making sure the sensor is clean.
Note:
If
the end of the probe is dried cleaned with a soft toothbrush the sensor will air saturate
quicker. To calibrate, place the probe back in the pipe and leave probe suspended
between the holes above the water for about twenty (20) minutes. Do not air calibrate if
air and water temperatures are + or – 10
o
C difference.
Using the enclosed pressure/altitude chart (fig-3) and the altitude of the location where
the unit will be housed, select the proper calibration value. Press the red
Read
button
on the faceplate of the unit. The operator will have two (2) minutes to adjust the Air
calibrate pot using a small screwdriver. After completing the adjustment, replace the
probe back in to the water.
Warning: If the pipe is submerged it has to be vented
below the point at which the probe is in the air due to treatment gases in the pipe.
4. Calibration using hand held DO meter:
Take handheld readings in the location where
the Fluoroprobe
TM
has been installed. As soon as the hand held reading has been
taken, make sure the selector switch is on DO, then press the red
READ
button. The
operator will have two ( 2 ) minutes to make the adjustment to the unit. Allow the
reading to stabilize before making adjustments. Uses the Air calibrate pot for 4ppm and
greater or use the zero for 4ppm and below. Adjust to the handheld DO meter reading.
The instrument is now ready to operate and needs no further adjustment.
Warning:. If the unit has just been put in the water, allow at least two (2 or 3) days
to equilibrate to the type of environment the sensor will be used in before
calibrating. Do not calibrate if probe has been removed from water, wait 30
minutes or longer before adjusting.
5. Probe and Sensor Maintenance:
The factory request that the probe be inspected at
least once a month. The probe can be washed down in the probe holder before the
inspection of the sensor takes place. A soft toothbrush should be used on the black
sensor on the end of the probe. Place back in water and allow at least (1) one hour to
stabilize.
