114
115
• Press ZERO key. The display will show “-0.0-” when the meter is zeroed and ready for measurement.
• Remove the cuvette and add the content of one packet of
HI 93750B-0 reagent. Replace the cap and gently mix for
one minute by slowly turning the cuvette upside down.
• Reinsert the cuvette into the instrument.
• Press TIMER and the display will show the countdown prior to the
measurement or, alternatively, wait for 2 minutes and press READ.
When the timer ends the meter will perform the reading. The
instrument displays the results in mg/L (ppm) of potassium (K).
• Press the
or
to access the second level of functions.
• Press the
Chem Frm
functional key to convert the result in mg/L of potassium oxide (K
2
O).
• Press the
or
to go back to the measurement screen.
INTERFERENCES
Interferences may be caused by:
Ammonium above 10 ppm
Calcium above 10000 ppm as CaCO
3
Chloride above 12000 ppm
Magnesium above 8000 ppm as CaCO
3
Sodium above 8000 ppm
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 93705
A
-0
Molybdate
6 drops
HI 93705
B
-0
Citric acid
1 packet
HI 93705
C
-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 128.
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
12
3
6
9
1’
Potassium LR
