Originating with the manufacturing of a basic electronic thermometer, TESTO, INC expanded into a company known globally for their development and design. From their start in 1957, TESTO, INC. is presently recognized as the leading global manufacturer of portable combustion efficiency analyzers and air emission analyzers.

Their markets range from chemical, pharmaceutical, biotech, to food service and production, with a product line that contains water analyzers, dataloggers, thermal imagers among others. TESTO, INC. continues expanding on their 50 years of experience by developing and perfecting instrumentation for the most demanding industries.