What is the "test strip" that came with my dishwasher for?

How to use the test strip:

1. Run water through the tap (1. min.)
2. Keep the strip in the water (1. sec.)
3. Shake the strip.
4. Wait 1. min.
5. Set the hardness level of your machine.

NOTE: The factory hardness level setting is “3”. If the water is well water or has a hardness level above 90 dF, we recommend that you use filter and refinement devices.