DPD dispenser for chlorine testing
Use in field tests for free or total chlorine in water for 5 mL and 10 mL samples.
- Dispense reagent with the press of a button.
- Avoid messy powder handling and leftover foil pouches.
- Refill dispenser quickly and easily.
- Eliminates foil packets.
- Recessed mouth fits different sized sample vials.
- Works with wide range of color cubes, color wheels, and colorimeters.
- Color coding distinguishes free and total chlorine tests.
- Dispenses reagent in one quick step.
- Reduces hands-on time.
- Refill vials screw on quickly and easily.
- U.S. EPA accepted—Standard Methods for the Examination of Water and Wastewater, Section 4500-Cl, G.
- Eliminates risk of powder trapped in corners of foil pouches.
How EZ DPD works
EZ DPD dispenses a premeasured dose of N, N-Diethyl-p-phenylenediamine (DPD) into a 5 mL or 10 mL sample. The DPD reacts with chlorine in the sample to produce a pink color change. The intensity of the color is proportional to the amount of chlorine in the sample.
Colorimetric test kits (not currently sold by IDEXX) allow the sampler to interpret the intensity of the color change, providing a quantitative measure of the amount of chlorine in the sample. EZ DPD detects chlorine between 0.1–3.5 parts per million (ppm).
How to use
A GUIDE TO USING EZ DPD
- Fill sample vial (not from IDEXX) with water you wish to test.
- Place EZ DPD over sample vial and press button once.
- Read results according to procedure explained in your test kit.
- To refill, unscrew empty reagent vial.
- Uncap refill vial and screw into dispenser top.
- EZ DPD works with a wide range of chlorine test kits.
Frequently asked questions
The Surface Water Treatment Rule of 1989 requires that distribution systems using surface water as a source and serving more than 25 people disinfect the distribution system or meet maximum HPC levels. Disinfectant residual level must be ≥ 0.2 mg/L (ppm), or the HPC level must be below 500 cfu/mL. The disinfectant residual must be present in ≥ 95% of samples for 2 consecutive months.
Testing frequency requirements:
|POPULATION SERVED||MINIMUM # SAMPLES/DAY|
Chlorine present as Cl2, HOCl, and OCl— is free available chlorine. The active chlorine in the water for disinfection is also called free chlorine residual.
Combined chlorine is that which is bound to other elements or organic compounds but is still an effective disinfectant. Combined chlorine has been found to be more effective than free chlorine in controlling postdisinfection bacterial growth. Chloramines are an example of combined chlorine.
The EZ DPD Test dispenser will deliver 0.04–0.09 grams of DPD powder each time the button is pressed.
Standard Methods for the Examination of Water and Wastewater, Section 4500-CI, G describes the DPD colorimetric method for field testing chlorine.
Remove the dispenser from the vial and clean it to dislodge any plugs. This can be done with a swab or other small device. The dispenser can also be cleaned with water. If you clean the dispenser with water, make sure it is dry before putting it back on a vial of reagent.
Resources & Tools
Water Customer Support
IDEXX Laboratories, Inc.
One IDEXX Drive
Westbrook, Maine 04092 USA