97
8.27. HARDNESS, TOTAL LOW RANGE
SPECIFICATIONS
Range
0 to 250 mg/L (as CaCO
3
)
Resolution
1 mg/L
Accuracy
±5 mg/L ±4% of reading at 25 °C
Light Source
LED with narrow band interference filter @ 466 nm
Method
Adaptation of the EPA recommended method 130.1.
REQUIRED REAGENTS
Code
Description Quantity
HI93735IND‑0
Hardness Indicator Reagent
0.5 mL
HI93735A‑LR
Hardness Low Range Reagent A
9 mL
HI93735B‑0
Hardness Buffer Reagent B
2 drops
HI93735C‑0
Fixing Reagent
1 packet
REAGENT SETS
HI93735‑00
Reagents for 100 tests (LR, 0 to 250 mg/L)
HI93735‑0
Reagents for 300 tests (LR ‑ 100 tests, MR ‑ 100 tests, HR ‑ 100 tests)
For other accessories see page 200.
MEASUREMENT PROCEDURE
• Select the
Hardness Total LR
method using the
procedure described in the Method Selection section
(see page 18).
• Add 0.5 mL of unreacted sample to the cuvette. Add
0.5 mL of
HI93735IND‑0
Hardness Indicator Reagent.
• With the plastic dropper fill the cuvette up to the
10 mL mark with
HI93735A‑LR
Hardness Low
Range Reagent A.
• Add two drops of
HI93735B‑0
Hardness Buffer
Reagent B. Replace the cap and invert 5 times to
mix.
HARDNESS
, T
OT
AL LOW RANGE
