Universal indicator papers have been impregnated with a mixture of several indicators

• Instant pH readings
• Accurate for a wide range of routine pH testing
• Convenient and portable for field use

The book format is particularly suitable for educational and industrial use. In schools this format is economical because the amount of paper per student can be carefully controlled.

On contact with the sample solution they assume a particular color. A check against the supplied color comparision table allows the pH to be determined.