Would someone please explain terminology?
- Thread starter Sjde
- Start date
The DPD test is a color matching test with shades of pink. Similar to the OTO chlorine test with shades of yellow. The user matches the pink color that develops in the sample to a set of color standards, or uses an electronic meter to make this reading.
The FAS-DPD test uses similar DPD test, except this method doesn’t require color matching. A powder is added and then the user adds drop by drop of the reagent to the sample containing DPD indicator. The number of drops needed to turn the sample from pink to colorless is multiplied by the chosen drop equivalency to determine the chlorine level.
The FAS-DPD method has several advantages. There’s no waiting time for full color development and the user does not have to be able to distinguish between shades of a color. Simple drop count multiplied by a factor give the results.
The FAS-DPD test uses similar DPD test, except this method doesn’t require color matching. A powder is added and then the user adds drop by drop of the reagent to the sample containing DPD indicator. The number of drops needed to turn the sample from pink to colorless is multiplied by the chosen drop equivalency to determine the chlorine level.
The FAS-DPD method has several advantages. There’s no waiting time for full color development and the user does not have to be able to distinguish between shades of a color. Simple drop count multiplied by a factor give the results.
Last edited:
An excellent explanation.
Also worth noting: the FAS-DPD test can measure up to 50 FC. The DPD test in most test kits is limited to 5.
Also worth noting: the FAS-DPD test can measure up to 50 FC. The DPD test in most test kits is limited to 5.
Oly
Gold Supporter
Taylor has a DPD test that ranges up to 10ppm. I find the DPD test easier to use while in the hot tub. 
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