91
8.25. HARDNESS, CALCIUM
SPECIFICATIONS
Range
0.00 to 2.70 mg/L (as CaCO
3
)
Resolution
0.01 mg/L
Accuracy
±0.11 mg/L ±5% of reading at 25 °C
Light Source
LED with narrow band interference filter @ 525 nm
Method
Adaptation of the Standard Methods for the Examination of Water and
Wastewater, 18th edition, Calmagite method.
REQUIRED REAGENTS
Code
Description Quantity
HI93720A‑0
Calcium Hardness Reagent A
0.5 mL
HI93720B‑0
Calcium Hardness Reagent B
0.5 mL
HI93720C‑0
Calcium Hardness Reagent C
1 drop
REAGENT SETS
HI93720‑01
Reagents for 100 tests
HI93720‑03
Reagents for 300 tests
For other accessories see page 200.
MEASUREMENT PROCEDURE
• Select the
Hardness (Calcium)
method using the procedure
described in the Method Selection section (see page 18).
• Rinse a graduated beaker several times with unreacted
sample, before filling it to the 50 mL mark with the sample.
• Add 0.5 mL of
HI93720A‑0
Calcium Hardness Reagent A
and swirl to mix.
• Add 0.5 mL of
HI93720B‑0
Calcium Hardness
Reagent B and swirl to mix. Use this solution to rinse
2 cuvettes before filling them up to the 10 mL mark.
# 1
# 2
HARDNESS
, CALCIUM