Ozone [with Cl₂ or Br₂]

Photometric test for Ozone in drinking and treated water with correction if chlorine or bromine are present

Fill to the 10 mL line with sample.

Use this to "blank" the instrument. Place in cell holder and press Blank.

Pour out sample leaving a few drops.

Add a DPD 4 tablet to those drops. Then, crush to form a paste.

Fill to the 10 mL line with further sample and stir.

Place the tube in the cell holder and press Measure. This value will be the uncorrected concentration of Ozone. Then, press Continue.

To a clean photometer tube, add a fresh 10 mL of sample.

Add a Glycine tablet and crush and stir.

Pour a few drops of this glycine treated sample into a second tube. Keep the remainder.

Add a DPD 4 tablet to those drops. Then, crush to form a paste.

Pour the remaining treated sample into this tube.

Place in the cell holder and press Measure to obtain the Ozone concentration after correction for chlorine or bromine.