Digital temperature and humidity data loggers

The Thermochrom family of iButtons (DS1921/DS1922) temperature data loggers track temperatures of vaccines, drugs, and reagents.

The Hygrochron family of iButtons (DS1923) adds an embedded humidity sensor to log both temperature and humidity. From the iButton Product Group of Dallas Semiconductor/Maxum, the iButton is a computer chip with a globally unique address, factory-lasered at time of manufacture, enclosed in a 16-mm stainless-steel case. They deliver or record data where needed.