The systems, used for data acquisition are known as data acquisition systems. These data acquisition systems will perform the tasks such as conversion of data, storage of data, transmission of data and processing of data.

Data acquisition systems consider the following analog signals.

• Analog signals, which are obtained from the direct measurement of electrical quantities such as DC & AC voltages, DC & AC currents, resistance and etc.

• Analog signals, which are obtained from transducers such as LVDT, Thermocouple & etc.

Types of Data Acquisition Systems

Data acquisition systems can be classified into the following two types.

• Analog Data Acquisition Systems
• Digital Data Acquisition Systems

Now, let us discuss about these two types of data acquisition systems one by one.

Analog Data Acquisition Systems

The data acquisition systems, which can be operated with analog signals are known as analog data acquisition systems. Following are the blocks of analog data acquisition systems.

• Transducer − It converts physical quantities into electrical signals.

• Signal conditioner − It performs the functions like amplification and selection of desired portion of the signal.

• Display device − It displays the input signals for monitoring purpose.

• Graphic recording instruments − These can be used to make the record of input data permanently.

• Magnetic tape instrumentation − It is used for acquiring, storing & reproducing of input data.

Digital Data Acquisition Systems

The data acquisition systems, which can be operated with digital signals are known as digital data acquisition systems. So, they use digital components for storing or displaying the information.

Mainly, the following operations take place in digital data acquisition.

• Acquisition of analog signals
• Conversion of analog signals into digital signals or digital data
• Processing of digital signals or digital data

Following are the blocks of Digital data acquisition systems.

• Transducer − It converts physical quantities into electrical signals.

• Signal conditioner − It performs the functions like amplification and selection of desired portion of the signal.

• Multiplexer − connects one of the multiple inputs to output. So, it acts as parallel to serial converter.

• Analog to Digital Converter − It converts the analog input into its equivalent digital output.

• Display device − It displays the data in digital format.

• Digital Recorder − It is used to record the data in digital format.

Data acquisition systems are being used in various applications such as biomedical and aerospace. So, we can choose either analog data acquisition systems or digital data acquisition systems based on the requirement.