224100 Nitrogen Test Kit, Model NI-8

Nitrogen Test Kit measures 0 - 3.0 mg/L NH₃-N in freshwater by Color Disc/Nessler reagent method. Model NI-8 may be used to evaluate 100 samples. The smallest increment is 0.1 mg/L NH₃-N. Nitrogen Test Set contains all apparatus, reagents and instructions in the easy-to-carry case for field analysis.

Nitrogen Test Set contains:

• Nessler Reagent (p/n 2119432)
• Nessler Ammonia Nitrogen Color Disc, 0-3.0 mg/L (p/n 9262600)
• Color Comparator Box (p/n 173200)
• 18 mm Plastic Viewing Tubes, with caps (p/n 4660004)

Procedure for NH₃-N measurement

Before you start take into account the following:

• Insert the color disc on the center pin in the color comparator box (numbers to the front).
• The required temperature of the sample is 20 °C.
• Pipet 1 drop of Rochelle salt reagent to the sample tube before adding the reagent to remove the hardness interference at the concentration higher than 6 gpg.

Testing procedure

Fill two tubes to the first line with freshwater sample. Place the first tube into the left opening of the color comparator box. Pipet 3 drops of Nessler reagent into the second tube and swirl to mix. The yellow color appears as the result of the reaction. After 1 minute, insert the second tube into the color comparator box, set the color comparator box in front of the light and rotate the color disc to find the color match. Analyze the result in mg/L in the scale window.

To record the test result as mg/L NH₃, multiply the test result by 1.2. To record the test result as mg/L NH₄⁺, multiply the test result by 1.3