Hanna Instruments HI 83099 - Manual (Page 58)

115 114
• 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 ▲ or ▼ to access the second level functions.
• Press the
Chem Frm key to convert the result in mg/L of potassium oxide (K
2
O)
• Press ▲ or ▼ to return to the measurement screen.
• For ULTRA HIGH RANGE samples: follow the procedure described at page 115.
INTERFERENCES
Interferences may be caused by: Chloride above 12000 ppm
Ammonium above 10 ppm Magnesium above 8000 ppm as CaCO
3
Calcium above 10000 ppm as CaCO
3
Sodium above 8000 ppm
Potassium HR
POTASSIUM ULTRA HIGH RANGE
For samples containing more than 200 ppm of Potassium: follow the sample preparation procedure
described at page 18 for CONCENTRATED SAMPLES. Then add to the graduated cylinder 20 mL of the
prepared sample (for HR) and fill the cylinder with demineralized water from the Demineralizer Bottle up
to the 100 mL mark.
Follow the MEASUREMENT PROCEDURE at page 114. Read the result in
mg/L of potassium on the display
and multiply the reading by 5 to obtain the actual concentration of Potassium.
Potassium HR
POTASSIUM HIGH RANGE
SPECIFICATIONS
Range 20 to 200 mg/L
Resolution 5 mg/L
Accuracy ±30 mg/L ±7% of reading at 25 °C
Typical EMC ±5 mg/L
Deviation
Light Source
Tungsten lamp with narrow band interference filter @ 610 nm
Method Adaptation of the Turbidimetric Tetraphenylborate method. The reaction between
Potassium and reagents causes turbidity in the sample.
REQUIRED REAGENTS
Code Description Quantity
HI 93750 A-0 Potassium Reagent 6 drops
HI 93750 B-0 Powder Reagent 1 packet
REAGENT SETS
HI 93750-01 Reagents for 100 tests
HI 93750-03 Reagents for 300 tests
For other accessories see page 132.
MEASUREMENT PROCEDURE
Note: for sample preparation follow the CONCENTRATED SAMPLES procedure at page 18.
• Select the Potassium HR method using the procedure
described in the Method Selection section (see page 12).
• Fill the cuvette with 10 mL of sample, up to the mark.
• Add six drops of HI 93750A-0, replace the cap and swirl
the solution.
• Place the cuvette into the holder and close the lid.
• Press the Zero key. The display will show “-0.0-” when the meter is zeroed and ready for
measurement.
10 mL