Hach DR/700 - Page 252

50-2
CYANURIC ACID, continued
4. After 2 seconds,
the display will show
a program number,
the concentration
units and the zero
prompt. Press the
PROGRAM key until
the lower display
shows program
number
50.000
The upper display
will show the S1
concentration. If
desired, press the
UP
ARROW
key to
display the other
standard.
5. Make the
displayed standard.
For each mg/L
displayed, pipet
1.00 mL from a
1000-mg/L cyanuric
acid stock solution
into a 1000-mL
volumetric flask. Add
demineralized water to
the mark. Cap and
invert to thoroughly
mix.
Note: To make a 25-mg/L
standard, pipet
25.00 mL of a 1000-mg/L
stock solution into the
flask. For a zero
concentration standard,
use only demineralized
water.
6. Fill a 25-mL cell
to the 25-mL line
with the displayed
standard.