For the detection of water and water vapour. On contact with water the paper changes from light to dark blue in a irreversible reaction, so even after it has dried out the water contact can be proven. Test the leak tightness of tubing or detect condensed water on pipes. Assess solvents in the lab to see that they are anhydrous. Use to check for water vapour in gas streams by first moistening the paper with anhydrous isopropanol then placing it in the gas stream.
These test papers allow the determination of non-metal chemical compounds. If you need to test for metals or metal containing compounds please see the range here.
They can be used to find out if compounds tested for are present in a quantity above a specific detection limit. Some of the described test papers can be used for non destructive testing of materials.