Datalogger An electronic device that records data over time or in relation to location either with a built in instrument or sensor or via external instruments and sensors. Datalogger Definition adapted from Wikipedia. See http://en.wikipedia.org/wiki/Data_logger ODM2 Equipment Type Controlled Vocabulary ODM2 Working Group A vocabulary for describing types of equipment used for making observations. Examples include sensors, batteries, radios, dataloggers, samplers, etc.