Color chart display colors: 0.2, 0.5, 1, 2, 5, 10 Color: Light blue to dark blue Measurement method: Colorimetric method Measurement range (mg/L): 0.2 to 10 Reaction time: 2 minutes Measurement interval: 6 levels Measurement item: PO phosphate (bottom 4) Measurement range: 0.2 to 10mg/l