Analog Signal Conditioning

Analog Signal Conditioning provides the operations necessary to transform a sensor output into a form necessary to interface with other elements of the process control loop.
Signal Conditioning can be classified into various types:

• Linearization
• Conversions
• Filtering and Impedance Matching
• Concept of Loading

Linearization 

The purpose of linearization is to provide an output that varies linearly with some variable even if the sensor output does not.

Conversions

Often, Signal Conditioning is used to convert one type of electrical variation into another. Two types of conversion are:

• Signal Transmission
• Digital Interface

Signal Transmission 

This gives rise to the need for converting resistance and voltage levels to an appropriate current level at the transmitting end and for converting the current back to voltage at the receiving end.

Digital Interface

The use of computers in process control necessitates the conversion of analog data into digital format by IC devices called A/D converters(Analog-Digital Converters).

Filtering and Impedance Matching

Often, spurious signals of considerable strengths are present in industrial envirouments. In many of such cases, it is necessary to use high-pass, low pass, or notch filters to eliminate unwanted signals from the loop. This might be accomplished by :

• Passive Filters(using Resistors, Capacitors and Inductors)
• Active Filters(using gain and feedback)