Hanna Instruments HI 83208-2008 User Manual

Page 32

Silica

SILICA

SPECIFICATIONS

Range

0.00 to 2.00 mg/L

Resolution

0.01 mg/L

Accuracy

±0.03 mg/L ±3% of reading

Typical EMC

±0.01 mg/L

Deviation

Light Source

Tungsten lamp with narrow band interference filter @ 610 nm

Method

Adaptation of the

ASTM Manual of Water and Environmental Technology, D859,

Heteropoly Blue method. The reaction between silica and reagents causes a blue tint in

the sample.

REQUIRED REAGENTS

Code

Description

Quantity

HI 93705A-0

Molybdate

6 drops

HI 93705B-0

Citric acid

1 packet

HI 93705C-0

Amino acid

1 packet

REAGENT SETS

HI 93705-01 Reagents for 100 tests
HI 93705-03 Reagents for 300 tests
For other accessories see page 73.

MEASUREMENT PROCEDURE

• Select the

Silica method using the procedure described

in the

Method Selection section (see page 12).

• Fill the cuvette with 10 mL of unreacted sample (up to

the mark).

• Add 6 drops of HI 93705A-0 Molybdate reagent.

Replace the cap and swirl the solution.

• Wait for 4 minutes, add the content of one packet of HI

93705B-0 Citric acid reagent and shake until it is completely
dissolved.

• Wait for 1 minute. This is the blank.

10 mL

x 6

1’

Phosphorus

• Add the content of one packet of HI 93706B-0 Phosphorus

Reagent B (Amino Acid) to the cuvette. Replace the cap
and shake gently until completely dissolved.

• Reinsert the cuvette into the instrument.

• Press TIMER and the display will show the countdown

prior to the measurement or, alternatively, wait for 5
minutes and press READ. When the timer ends the
meter will perform the reading. The instrument displays
the results in mg/L of phosphorus (P).

• Press the or to access the second level of functions.
• Press the Chem Frm functional key to convert the result in mg/L of phosphate (PO

) and phosphorus

pentoxide (P

• Press the or to go back to the measurement screen.

INTERFERENCES

Interference may be caused by:
Sulfide
Chloride above 150000 mg/L
Calcium above 10000 mg/L as CaCO

Magnesium above 40000 mg/L as CaCO

Ferrous iron above 100 mg/L