Most Widely used DPD Chlorine Tablets for Determining Free and Combined Chlorine
DPD chlorine tablets employ DPD indicator (diethyl-p- phenylenediamine) to distinguish levels of free, combined, and total chlorine in a simple test sample. DPD chlorine tablets designated “Instrument Grade” are suitable for use with colorimeters and spectrophotometers. For more information on chlorination and measurement of chlorine, order The Chlorine Handbook (Thomas number 0535C36).
DPD No. 1 Tablet is used to measure free available chlorine in water. Range: 0 to 10 ppm for approximately 10 mL sample size. Shelf life: approx. three years. Instrument Grade.
DPD No. 1R Tablet contains disintegrant. Not suitable for use with colorimeters or spectrophotometers, visual comparators only.
DPD No. 2 Tablet is used to measure monochloramine level when added to sample after DPD No. 1
DPD No. 3 Tablet is used to measure dichloramine or combined chlorine. Instrument Grade.
DPD No. 3R Tablet contains disintegrant. Not suitable for use with colorimeters or spectrophotometers, visual comparators only.
DPD No. 4 Tablet is used to measure total residual chlorine in water. Range of 0 to 10 ppm.
DPD No. 4R Tablet contains disintegrant. Not suitable for use with colorimeters or spectrophotometers visual comparators only.