MIOX AE Series Operators Manual
102-00085-E
Page
44
Thus, add 2 mL of oxidants to 98 mL of sample water for the first FAC reading
3. Determine the doses for subsequent measurements.
Dilute the oxidant as determined above and after 30 minutes, take an FAC reading. If FAC is
unmeasurable, all of the oxidants have been consumed and you need doses of 10, 15, and 20 ppm for
subsequent testing; otherwise if FAC has not significantly diminished, use 1, 3, and 5 ppm doses for
subsequent testing. In this case, assume that the reading was 2.5 ppm after 30 minutes, indicating you
should use test doses of 1, 3, and 5 ppm.
Setup Calculations
Use the formulas given above to determine the amount of oxidant and sample water to use (based on
100 mL samples) for each of the doses. The sum of your oxidant and sample water volumes should add
up to 100 mL since it provides enough volume for multiple FAC measurements at the various testing
times.
Example:
Determine the oxidant and sample water volumes for the 1, 3, and 5 ppm doses. Given that MIOX OSG
is still generating an oxidant concentration of 250 ppm.
1 ppm
3ppm
5ppm
Dilution Factor (X) 250/1 =
250
250/3
=
83.3
250/5
=
50
mL of Oxidant
100/250 =
0.4
100/83.3
=
1.2
100/50
=
2
mL of Sample Wate
r
100-0.4 =
99.
6 100-1.2
=
98.8
100-2
=
98
For a
1 ppm
dose,
0.4 mL
of oxidant should be mixed with
99.6 m
L of sample water For a
3 ppm
dose,
1.2 mL
of oxidant should be mixed with
98.8 mL
of sample water For a
5 ppm
dose,
2.0 mL
of
oxidant should be mixed with
98 mL
of sample water
Procedure
Stagger preparation of each dilution by several minutes to allow enough time for accurate analysis of
FAC at each dilution. FAC readings should be taken at the following times: T = 0, 30 minutes, 60
minutes, and 90 minutes. Readings beyond 90 minutes are determined by interpretation of data from
the first 90 minutes.
• Accurately measure the volume (mL) of calculated sample water and place in a glass jar.
• Accurately measure the volume (mL) of oxidant required.
• Add oxidant to sample water jar and swirl briefly to mix.
• Immediately measure and record the FAC concentration and time the reading is taken (time
= 0).
