ATI
Model A15/82 Fluoride Monitor with Auto-Calibration
23
O&M Manual
Rev-G (6/10)
OPERATION
With the chemistry module in operation and power turned on to the monitor, the system should now be
displaying a fluoride concentration from the sample. The value measured initially will probably be fairly close to
the actual value, but the monitor is not factory calibrated. While the monitor contains an automatic calibration
feature, a manual 2-point calibration must be done at startup.
The calibration procedure will require preparation of two fluoride standards. A 500 cc bottle of 100 PPM
fluoride standard is supplied with the monitor system. Standards of 1 PPM and 10 PPM should be prepared for
use in calibration. Two bottles are supplied for holding the mixed standards. You will also need a pipette and a
volumetric cylinder for mixing your standards.
For mixing the 1 PPM standard, pipette 1 cc. of the 100 PPM standard into a 100 cc volumetric flask.
Dilute to 100 cc using either unfluoridated drinking water or distilled water. Using unfluoridated water from the
system has the advantage of producing a standard with the same background composition of the water you will
be monitoring. If this is not feasible, distilled water can be used instead as there will be little real difference in the
end result. Pour the mixed standard into the 1 PPM standards bottle and then rinse the volumetric flask with
distilled water.
For the 10 PPM standard, pipette 10 cc. of the 100 PPM standard into the volumetric flask and dilute to
100 cc. as before. Pour this standard into the bottle marked 10 PPM. Keep these two standards bottles capped
for use in calibration checks as needed.
CALIBRATION
The fluoride monitor electronics is designed to allow up to a 5 point calibration for ion selective sensors.
For fluoride measurement, only a two point calibration is necessary. The standards are fed into the chemistry
module using an extension tube supplied with the unit. Remove the sample pickup tube from the overflow
chamber and connect the extension tube. A barb fitting is supplied on the extension tube for this purpose.
Follow the procedure below.
1. Place the extended pickup tube into the 1 PPM standard mixed previously and allow the standard to be
pumped into the chemistry module.
2. Press the MODE key on the monitor once and the display will indicate “ppm X point cal”. Press the CAL key
once and the display will read “CAL POINT Nr. 1”. Press CAL again and the display will read “CAL P1: X.X
mV”. This display shows the current mv. signal from the fluoride sensor (this value will normally be around
+40 mV for the glass electrode and -350 mV for the polymer sensor.)
3. After the 1 PPM standard has been flowing for 5 minutes, the mv. signal should be stable to within a few
tenths of a millivolt. Press ENTER and the display will indicate “P1 DECADE: 100.0”. Press the DOWN
arrow and the display will read “P1 VALUE: 10.00”. Press ENTER and then use the DOWN arrow to adjust
the value to 1.00 (hold button down and display will scroll down). Then press ENTER.
4. The display will now indicate “CAL POINT Nr. 2”. Remove the standards pickup tube from the 1PPM
standards bottle and place it into the 10 PPM standards bottle. Allow the system to run for about 5 minutes
on the 10 PPM standard.
5. Press CAL and the display will read “CAL P2: X.X PPM”. As before, the millivolt value should be fairly
stable after the 10 PPM standard has been flowing for 5 minutes (this value will normally be around -15 mV
