pH indicators and pH strips
pH test papers
Ahlstrom pH test papers are impregnated with one or several indicators that show a distinctive color when exposed to a specific condition. They allow a quicker and less expensive test in applications where the accuracy of an electronic pH meter is not needed.
Universal pH indicator papers are available in different ranges of pH to give the user the level of accuracy needed.
Additional test papers for qualitative determination are also available for industrial application and educational purpose.
pH test strips
Ahlstrom pH test strips have small squares of paper, each prepared with a different indicator, attached to a thin but flexible plastic strip for improved handling. pH indicator are strongly bonded to the cellulose fibers to prevent bleeding of the colors to give a more precise measurement and also prevent contamination of the test solution.
Reliable pH measurement can be obtained even in weakly buffered solutions and the test strips can remain in the test solution until the final reaction color is obtained.
| Scale | Interval |
| pH 0-10 | 1 |
| pH 0-14 | 1 |
| pH 0.5-5 | 0.5 |
| pH 5-9 | 0.5 |
| pH 6.4-8 | 0.3 |
| pH 6.5-10 | 0.5 |
Various scales are available with diverse forms (roll, strips).