21
METHOD PROCEDURE
• Insert the cuvette into the holder and ensure that the
notch on the cap is positioned securely in the groove.
• Press
Read.
The display will show a 6 minute countdown prior to the measurement.
To skip the timer, press
Read
twice
.
When the timer ends the meter will perform
the reading. The instrument displays concentration in
µg/L
of
chromium (Cr
6+
).
• 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
µg/L
of
chromate (CrO
4
2¯
)
and
dichromate (Cr
2
O
7
2¯
)
.
INTERFERENCES
Interference may be caused by:
• Vanadium above 1 mg/L, wait for 10 minutes before reading to remove the
interference
• Iron above 1 mg/L
• Mercurous and mercuric ions slight inhibition of the reaction
