There is a strong correlation between the ph of the body’s internal environment and ph paper help you to maintain good healthy body by testing many usual everyday substances, including moisturized soap, lemon juice, milk, liquid detergent, moisturized soil, saliva, urine, sweat…etc. The test strip color changes must be matched with the ph scale color chart within about 15 seconds. The scale reads from 1 to 14.1 – 3 Indicates a very acidic substance.4 – 6 Indicates an acidic substance.7 Indicates neutral.8 – 11 Indicates alkalinity (note: only for strong acid and base. It will not work on water).