Ph Indicator Paper

pH Indicator paper strips are manufactured by impregnating special quality filter paper with indicator or mixed indicator solutions. The convenience of using indicator papers for the rapid determination of pH values has led to many applications of this item in laboratory and industries.

Although there are a number of commercially available universal pH indicators, most are a variation of a formula patented by Yamada in 1923. Normally, the test solution causes the colour of the indicator strip to change depending upon the pH at 25A C, considered the standard temperature. They are used to test the alkalinity or acidity of a solution or substance such as soil. pH papers are usually sold as strips. These strips of paper change color when they come in contact with the material or solutions being tested. As most naturally occurring organic compounds are weak protolytes, carboxylic acid & amines, pH indicators find many applications in biology & analytical chemistry.
For optimal accuracy, the difference between colors should be as clear as possible. For this purpose, pH indicators are made by the addition of several chemicals to give precise indication.