27
• Remove the cuvet.
• Add carefully the content of
one packet of HI 93756A-0
Ca Hardness 1 Reagent.
Replace the cap and shake
vigorously for 10 seconds.
Note
: Pay attention not to
spill reagent otherwise full
color development may be
inhibithed.
• Add the content of one packet
of HI 93756B-0 Ca Hardness
2 Reagent. Replace the cap
and shake vigorously for 10
seconds.
• Replace the cuvet into the holder and
ensure that the notch on the cap is
positioned securely into the groove.
• Press TIMER and the display will show the countdown prior to
measurement. Alternatively, wait for 2 minutes and press READ
DIRECT. In both cases “SIP” will blink during measurement.
• The instrument directly displays concentration in
mg/L of calcium
as CaCO
3
on the Liquid Crystal Display.
• To convert the result to mg/L of calcium (Ca
2+
), multiply by a
factor of 0.4.
INTERFERENCES
Interference may be caused by:
Orthophosphate: precipitate Calcium at the pH of the test.
Alkalinity above 150 mg/L CaCO
3
may cause cloudiness. To resolve
this, neutralize the sample with diluted HCl.
Calcium Hardness
