Recorder (Data Logger):
Technically speaking, a data logger is any device that can be used to store data. This includes many data acquisition devices such as plug –in boards or serial communication systems which use a computer as a real time data recording systems.
However, most instrument manufacturers consider a data logger a stand alone device that can read various types of electrical signals and store the data in internal memory for later download to a computer.
The advantage of data loggers is that they can operate independently of a computer, unlike many other types of data acquisition devices. Data loggers are available in various shapes and sizes. The range includes simple economical single channel fixed function logger to more powerful programmable devices capable of handling hundreds of input.

Temperature and Process Controllers:

Temperature and process controllers are used over a vast range of industrial, scientific and commercial applications. These controllers automatically adjust outputs based on sensor feedback working in concert to control process variable such as temperature, flow, pressure and relative humidity, as to achieve an optimized and stable process.