A mixture of dyes that changes colour gradually over a range of pH and is used (especially as indicator paper) in testing for acids and alkalis.
〔化〕通用指示剂
Example sentencesExamples
The groups are regular acid-base indicators, mixed indicators, screened indicators, universal indicators, pH sticks, litmus paper (embedded in gel or litmus in a gel), natural food indicators, fluorescent indicators, luminescent indicators, irreversible indicators and a miscellaneous group.
The easiest universal indicator to prepare is red cabbage juice.