22
METHOD PROCEDURE
• Press the
key and use the functional keys to select
Chemical Form
.
• Use the functional keys and press
Select
to change the displayed chemical formula
to
mg/L
of
aluminum oxide (Al
2
O
3
)
.
INTERFERENCES
Interference may be caused by:
• Alkalinity above 1000 mg/L
• Phosphate above 50 mg/L
• Iron above 20 mg/L
• Fluoride must be absent. If the fluoride concentration is known, the aluminum
concentration can be determined using the graph below:
To use the fluoride interference graph:
1. Follow the measurement procedure to obtain the aluminum concentration.
2. Locate the aluminum reading on x-axis.