pH-Fix 7.0-14.0 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 7.0-7.5-8.0-8.5-9.0-9.5-10.0- 10.5-11.0-11.5-12.0-12.5-13.0-13.5-14.0