pH-Fix 2.0-9.0 indicator strips with chemically bound indicators are the bench mark for pH testing with test strips. The fixation prevents bleeding and therefore contamination of the sample. measuring range: pH 2.0-2.5-3.0-3.5-4.0-4.5- 5.0-5.5-6.0-6.5-7.0-7.5-8.0-8.5-9.0