Instrumentation System

Functional elements of an Instrumentation System:

Instrumentation System
Instrumentation system


Any instrumentation system can be described with the help of a block diagram.The block diagram of an instrumentation system describes the essential elements and their
functions in a measuring system.

Fig. shows the block diagram showing the functional elements of an instrumentation system.

                    Instrument system



The elements can be grouped as:

Primary sensing element.
Data conditioning element.
Data presentation element.

Each element comprises of a number of distinct components that perform a particular function in the measurement procedure.The function of each element is important.

 Primary Sensing Element:


To the primary sensing element the quantity to be measured is applied.e.g.in an ammeter, coil carrying current to be measured is a primary sensing element.

Generally a transducer follows a primary sensing element.The transducer converts the measured to corresponding electrical signal.

 Variable Conversion Element:


The output from the primary sensing element is in electrical form like voltage,
frequency or any other electrical parameter.

Such output is not suitable for the actual measurement system.e.g. if the measurement system is digital then the analog electrical signal obtained from the primary sensing element is not suitable for the digital system.

Hence a variable conversion element like A/D converter is required.

Some instruments may require more than one variable conversion element.While conversion the original data must be retained.

 Variable Manipulation Element:


The level of output from the earlier stage may not be sufficient enough to drive the next stage. Thus, the variable manipulation element manipulates the signal, preserving the original nature of the signal.

The variable manipulation element can be placed before the variable conversion element if required.

If the level of signal obtained from earlier stage is large then it must be reduced.In such cases attenuators are used as variable manipulation elements.

In some cases the output of transducer is affected due to unwanted signals like noise. These signal must be processed by some processes like clipping, clamping etc. To achieve the signal in undistorted from This process is called as signal conditioning.

Data Transmission Element:


When the elements of the system are physically separated , it is essential to transmit the data from one stage to other. it is obtained by a data Transmission Element

Data Presentation Element:


Data that is transmitted is used by the system for monitoring, controlling or analysing purpose. thus the person who is handling the instrument must get the information in proper form,according to the purpose for which it is required. This function is done by a data Presentation element.









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