chemical indicator
a substance used to assist in the classification of another substance
Liquid contact indicator
indicator in the form of a sticker that changes color after contact with liquids
chemical oxygen demand
measure of the amount of oxygen that can be consumed by reactions in a solution
sunshine duration
climatological indicator, measuring duration of sunshine in given period
time temperature indicator
chemical indicator used for food safety and other applications
pH indicator
halochromic chemical compound added in small amounts to a solution so the pH of the solution can be determined visually