DPD No. 1 Tablets for Free Chlorine

Overview

DPD No. 1 tablets measure free chlorine, the fraction of the residual still available to disinfect. The tablet gives a pink colour whose depth the instrument converts to a reading, which makes this the everyday check on potable water plants, reticulation systems, pools and cooling circuits. Read the sample promptly, because combined chlorine will creep into the result if it stands.

Key features

• Reads free chlorine, the disinfecting fraction, rather than total chlorine
• One tablet per test, so there is no measuring or decanting of liquid reagents
• Foil-sealed strips keep unused tablets dry until they are needed
• Supplied in the standard 250-tablet pack, item code TbsPD1250

DPD No. 1 tablets specifications

Applications

Potable water disinfection and SANS 241 monitoring, reticulation and reservoir sampling, swimming pools and spas, cooling towers, food and beverage plants, and any site holding a free chlorine residual within a set band.

Why buy DPD No. 1 tablets from Hadron Group

Hadron Group supplies water treatment chemicals, dosing equipment and analytical products throughout South Africa and the SADC region. We hold DPD No. 1 tablets as standard stock in the 250-tablet pack, we can supply the matching photometer, cuvettes and spares, and our technical team will help you settle on the right test set for your plant. Browse the full reagent range or ask us for a quote.

Frequently asked questions

What is the difference between free and total chlorine?
Free chlorine is what is still available to disinfect. Total chlorine adds the combined fraction that has already reacted with ammonia and organics. The gap between the two is the combined chlorine, and a widening gap usually means the residual is under strain.

Photometer grade or rapid grade — which do I need?
Photometer grade is formulated for instruments that read a cuvette. If you work with a visual comparator or colour disc, ask us for the rapid-dissolving grade instead.

How should the tablets be stored?
Keep them sealed, cool and dry, and work through the oldest strip first. Once a strip is opened the tablets take up moisture, so use them promptly.