Comparator / color disc for 6,6 - 8,4 pH

Description

Before using the one-parameter test place the colored disc on the center post in the color comparator box (numbers on the front) and rinse the tubes with the sample. After finishing to do a test rinse the tubes with deionized water.

For more accurate results use a buffer solution as a sample. Chlorine with a concentration of more than 1 mg/L interferes with the test. To remove chlorine from a sample, add 1 drop of 0.1 N sodium thiosulfate solution per 25 ml of sample and mix and then use this dechlorinated sample in the test procedure. Sodium thiosulfate removes a maximum of 10 mg/L chlorine from the sample.

Step-by-step instructions for testing ph with the test-kit Hach 17H:

1. Fill the tube with a sample to 5 ml;
2. Place the test tube - on the left in the color comparator box;
3. Add 8 drops of indicator solution to the second tube;
4. Rotate the tube to mix the sample;
5. Place the second tube in the color comparator box;
6. Keep the color comparator box out in the light (use sunlight or a desk lamp). Rotate the color wheel until the colors match. If the color is the same between two segments use the value in the middle of the two segments;
7. Compare results with a pH scale.