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Dissolved Oxygen

Saurabh Levin edited this page Mar 6, 2019 · 5 revisions

Conducting a Test

Things You Will Need

  1. 1 vial of Reagent (Refer to the section on reagent preparation below)

  2. A smartphone with the ffem Collect and ffem Water apps installed, and an alignment sticker around the camera

  3. A Cuvette and pipe

  4. A 10 ml measuring tube

  5. Tissue Paper

  6. A sample to test


  1. Open the ffem Collect app, and select "Fill Blank Form". Select the form you need to fill out.
  1. Answer all the questions in the form, swiping left to go to the next questions. When you reach the water quality questions, launch the test for Dissolved Oxygen
  1. Rinse the empty cuvette and measuring tube twice with the sample to remove any traces of previous solutions.

  1. Measure 10 ml of the sample with the measuring tube.

  1. Open the vial of Reagent and add it to the measuring tube.

5.Close the lid of the measuring tube and shake it to ensure proper mixing of the reagent and sample.

  1. Pour the contents of the mixing tube into the provided cuvette. Close the lid and fit the cuvette into the pipe.


  1. Launch the test on the app selecting "No Dilution" on the next screen.
  1. Place the phone face down, and use the sticker to help center the cuvette over the camera. Wait about a minute for the test to complete - you will hear 6 beeps and a "Test Completion" sound.
  1. You should receive a contaminant concentration value in ppm. Tap Accept Result to return to the survey.
  1. Empty the contents of the cuvette and rinse it once.
  1. Complete the rest of the survey, and submit it once you have filled in all the forms.

Reagent preparation

Things You will Need

  1. 1 Bottle each of Reagent A and B
  1. A measuring cylinder

  2. Empty vials


  1. Take 10 ml of Reagent A in the measuring tube. add 2.5 ml of Reagent B, so that the total volume of the solution is 12.5ml.
  1. Leave the solution to react. In about 10 minutes, the the colour should change from Dark red to yellow

  2. Fill the empty vials with the mixed reagent up to the (0.5ml) line for easy testing on the field.

Validation Testing

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