Editing Data logger (section)

{{Short description|Recording device}}
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{{Distinguish|Computer log file}}
{{For|path tracking devices|GPS tracking unit#Data loggers}}
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[[Image:Datalogger.jpg|thumb|Data logger Cube storing technical and sensor data]]
A '''data logger''' (also '''datalogger''' or '''data recorder''') is an electronic device that records data over time or about location either with a built-in [[Scientific instrument|instrument]] or [[sensor]] or via external instruments and sensors. Increasingly, but not entirely, they are based on a digital processor (or computer), and called digital data loggers (DDL). They generally are small, battery-powered, portable, and equipped with a microprocessor, internal memory for data storage, and sensors. Some data loggers interface with a personal computer and use software to activate the data logger and view and analyze the collected data, while others have a local interface device (keypad, LCD) and can be used as a stand-alone device.

Data loggers vary from general-purpose devices for various measurement applications to very specific devices for measuring in one environment or application type only. While it is common for general-purpose types to be [[Computer program|programmable]], many remain static machines with only a limited number or no changeable parameters. Electronic data loggers have replaced [[Chart recorder|chart recorders]] in many applications.

One primary benefit of using data loggers is their ability to automatically collect data on a 24-hour basis. Upon activation, data loggers are typically deployed and left unattended to measure and record information for the duration of the monitoring period. This allows for a comprehensive, accurate picture of the environmental conditions being monitored, such as air temperature and relative humidity.

The cost of data loggers has been declining over the years as technology improves and costs are reduced. Simple single-channel data loggers can cost as little as $25, while more complicated loggers may cost hundreds or thousands of dollars.