Data Logger Information
A data recorder or data logger is an electronic device that records data over time. These days most, but not all data loggers are based on a digital processor (or computer). They generally are small, battery powered, portable, and equipped with a microprocessor, internal data storage, and sensors. Some data loggers interface with a PC with special software to activate the data logger and view and analyze the collected data, while others have a built-in interface device (examples include a keypad or LCD) and can be used as a stand-alone device.
Data loggers come in a number of different varieties. These range general purpose types for a variety of common measurement applications to very specific devices for measuring in a special environment. It is common for general purpose types to be programmable; however, many remain as static machines with only a limited number of options. Electronic data loggers have replaced chart recorders in many industries.
The terms data logging and data acquisition are often confused or used interchangeably. However, in a historical context they are quite different. A data logger is a type of data acquisition system, but a data acquisition system is not always a data logger. Data loggers typically have slower sample rates. A maximum sample rate of 1 Hz may be considered to be very fast for a data logger, yet very slow for a traditional data acquisition system. Data loggers are almost always stand-alone devices, while typical most data acquisition systems must remain connected to a computer to acquire data.
The unattended and remote nature of many data loggers implies means many devices must operate from a DC power source, such as a battery. Solar power may be used to supplement these power sources. These constraints have generally led the data logger industry to construct their devices so that they market are extremely power efficient relative to computers. In many cases they are required to operate in harsh environmental conditions where a standard computer would not function reliably or possibly at all. One of the primary benefits of using a data logger is the 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 period that data is being collected from. This allows for a comprehensive, accurate picture of the environmental conditions being monitored, such as air temperature and humidity.
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