Ideal for semi-quantitative evaluation of water hardness (total hardness). Simple use. Suitable as a fast first test of hardness values. Range from 0 °d to over 25 °d. Division into the following degrees of hardness: <3 °d, >5 °d, >10 °d, >15 °d, >20 °, >25 °d. Test stick is dipped into the water sample. The colour changes and hardness can be evaluated after 1 min by comparison with supplied scale. Attention: Test paper should not be touched with fingers. One pack contains 100 test sticks 6 x 95 mm. Conversion: 1 °d = 1.8 °f = 1.25 °e = 17.8 mg/l CaCO₃