The DPD Method
In the USEPA-approved DPD methodology, free chlorine reacts with DPD to form a pink product. When ammonia or amines are present, some of the chlorine may exist as combined chlorine. Combined chlorine will not interfere with the free chlorine results, provided the readings are taken at one minute. To determine total chlorine (the sum of free and combined), use the A-2500 Activator Solution (potassium iodide) supplied in the kit. Results are expressed as ppm (mg/L) Cl2.
Material Safety Data Sheets are provided in test kits.
CHEMets ampoules are designed for maximum simplicity and accuracy. Each glass ampoule is 7 mm in diameter, 100 mm in length, with a tapered, pre-scored tip; reagents are vacuum-sealed inside.
Various free halogens and halogenating agents produce colour with the reagent. Chromate in samples below 25 ppm will not interfere with results. Results are expressed as ppm (mg/L) O3.
Ordering Information:
Analyte: OZONE
Method: DPD METHOD
Type: CHEMet
K-7404 Ozone 0-0.60 & 0.6-3.0 ppm
Test kits contain 30 ampoules, comparators, accessory solutions (when necessary), snap cup, MSDS, and instructions.
R-7404 Refill, 30 CHEMet ampoules
A-7400 Activator Solution, six 10 mL bottles
A-0013 Sample Cup, 25 mL, package of six
C-7401 Comparator, 0-0.6 ppm
C-7402 Comparator, 0.6-2 ppm