MIOX AE Series Operators Manual
102-00085-E
Page
45
• Repeat the above steps for the other dilutions, measure each at time = 0 before preparing
the next dilution, and then take FAC readings at 30, 60, and 90 minutes. Generate a table
similar to the one given in the example below.
Example:
Fill out the table properly and completely. The oxidant solution must be diluted to 1 ppm, 3 ppm, and 5
ppm doses as determined in the previous example. The FAC residual is measured in 30-minute intervals
until the chart is filled out as below (measurements are based on assumed tests for this example):
Sample
A (1
ppm)
Time
(o’Cloc
k)
Sample
B (3
ppm)
Time
(o’Cloc
k)
Sample
C (5
ppm)
Time
(o’Cloc
k)
t = 0
0.4 12:00
2.1 12:05
4.0 12:10
t + 30
0.08 12:30
2.0 12:35
2.5 12:40
t + 60
0.0 1:00
2.0 1:05
2.5 1:10
t + 90
0.0 1:30
1.8 1:35
2.4 1:40
Oxidant Demand Determination
After 90 minutes, determine which sample has the FAC residual nearest to the desired residual specified
by the water system operator. If a desired residual is unknown, look for a FAC slightly greater than 0.2
ppm, which is usually the standard required by the state.
Subtract the selected FAC reading from the initial FAC dose for the corresponding sample. This signifies
how much of the oxidants were consumed by the water and thus how much of an oxidant demand there
is in the sample water.
Example:
Determine the oxidant demand of the water. In this case, let’s assume the operator wants a 1.0 FAC
residual in the water system. Looking at the bottom row (t + 90 minutes) of the chart filled out above,
note that Sample B at 1.8 ppm is closest to the desired residual. The initial FAC dose in this case was 3
ppm, so the oxidant demand of this water is 1.2 ppm (3.0 - 1.8 = 1.2). (This means that the operator
must dose at 2.2 ppm (1.2 + 1.0 = 2.2) to achieve his desired residual of 1.0 ppm.
Chlorine Production Testing
Calculating chlorine production alone is the easiest way of checking the performance of a MIOX mixed-
oxidant or MIOX sodium hypochlorite system. A cell yielding a reading of 3200 ppm when it should be
reading 3600 ppm may not be old and depleted -- the flows may also be high.
Total Chlorine Production = Chlorine Concentration X Volumetric Flow per unit time
Follow the steps below to correctly determine the total chlorine production of the system.
Equipment Needed