PH Indicator Paper, PH Indicator Strips, PH Test Strips, PH Paper

1. PH Indicator Paper used to roughly measure the size of the solution pH (or acid-base strength). 

2. H Indicator Strips encountered in acid-base strength of different solution, showing different colors, and standard colorimetric card control determine the pH value. 

3. PH Test Strips, Coincidence color: red (pH = 1 or 2), orange (pH = 3 or 4), yellow (pH = 5 or 6), green (pH = 7 or 8), green (pH = 9 or 10), blue (pH = 11 or 12), purple (pH = 13 or 14).