The color change of the gauge should match the pH scale color chart in about 15 seconds. Different pH values have different discoloration ranges, and compare the color map ratio: the smaller the number, the stronger the acidity, the larger the value, the stronger the alkalinity. < p>Please do not immerse the pH test paper in the test solution. This may cause incorrect display of test results. Put a drop of the test on the pH paper. It will perfectly indicate the actual acidic or basic substance. There is a strong correlation between the pH of the body’s internal environment, and pH test strips are tested for many commonly used substances, including the hydrated soap, lemon juice, milk, liquid detergents, wet soil, saliva, urine, sweat, etc. .