INTRODUCTION TO INSTRUMENTATION :
The technology of using instruments to measure and control the physical properties of materials are called instrumentation. When instruments are used for the measurement and controlling of industrial manufacturing, conversion or treatment process, the term “PROCESS INSTRUMENTATION” is applied. The result is called a “CONTROL SYSTEM”.
PURPOSE OF INSTRUMENTATION :
The basic purpose of instrumentation in an industry is to obtain maximum output from the industry with the minimum usage of raw materials, time, energy, manpower, etc. With the growth of continuous manufacturing the need for continuous measurement of pressure, temperature, level and flow became necessary.
WHAT IS AN INSTRUMENT :
An instrument is a device that is used to measure and control physical properties of materials. An instrument converts the parameter that we need to measure into a readable format.
APPLICATIONS OF INSTRUMENTATION :
- Collecting and sending information about a measured variable.
- Displaying and recording information about a measured variable
- Comparing the value of measured variable to a set point.
- Controlling the process variable according to the corrective signal from controlling device.
- Initiating an alarm when the measured variable is either too high or too low.
TRANSDUCERS AND SENSORS :
Transducer is device which converts one form of energy into another. A sensor is a converter that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument.
Sensors are of two types
- Analog sensor
- Digital sensor
Analog produces an analog output proportional to a change in parameters and Digital produces an on/off type output.
Transducers are of two types
- Active transducer
- Passive transducer
An active transducer is a transducer whose output is dependent upon sources of power, apart from that supplied by any of the actuating signals, which power is controlled by one or more of these signals. While passive transducers are those which does not need an external source. Passive transducers directly produce electric signals without an external energy source.