Delivery: K-7013 Nitrite Vacu-vials test kit is used to measure the concentration of nitrite in water with the azo dye formation method. It comes in a cardboard box and contains everything needed to perform 30 tests: thirty ampoules, acidifier solution, 25 ml sample cup, ampoule blank, and instructions. This kit requires the use of a CHEMetrics direct-readout photometer or a spectrophotometer capable of accepting a 13 mm diameter round cell. Instrument sold separately.