Hach DR2400 - Page 653

DR/2400
Phosphorus, Reactive (Orthophosphate)
PhosphorusReac_UniCell_Asc_Eng_Ody.fm Page 1 of 4
• Adjust the pH of preserved samples between pH 2–10 before testing.
• Clean the outside of the vial before placing it in the instrument. Wipe with a damp towel, followed by a dry one.
• Use the standard solution or standard addition method to verify results (see Accuracy Check on page 3).
• See Section 3.2.4 in the procedure manual for information on adjusting the calibration curve.
• Make sure the temperature of the water sample and the sample vial is between 18–20 °C. Temperatures outside of this range will
affect the color of the reaction and may give inaccurate results.
• Underrange appears on the display when the instrument is zeroed or when the determined sample concentration is below the
operating range listed for this method.
Phosphorus, Reactive
(Orthophosphate)
Ascorbic Acid Method
UniCell™ Vials
Scope and Application: For water, wastewater, boiler water,
surface water, and process control
(1.5 to 15.0 mg/L PO
4
3–
)
1. Touch
Hach Programs.
Select program
806 Phosphate, HCT 121.
Touch
Start.
2. Pipet 1.0 mL of
sample into a sample
vial.
3. Pipet 0.4 mL
of Reagent B
(HCT 121/122 B) into
the sample vial.
Close the Reagent B bottle
immediately after use.
4. Screw a light green
UniCap C (HCT 121 C)
onto the sample vial.
Tips and Techniques
UniCell Vials
Hach Programs