ELECTRONIC INSTRUMENTATION Reference Books • Measurement System : Ernest O Doebelin • Measurement System : Ernest O Doebelin • Electronic Instrumentation : H.S Kalsi
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ELECTRONIC INSTRUMENTATION
Reference Books Measurement System : Ernest O Doebelin Electronic Instrumentation : H.S Kalsi
Reference Books Measurement System : Ernest O Doebelin Electronic Instrumentation : H.S Kalsi
Electronic Instrumentation Instrumentation is a branch of engineering
that deals with the measurement and controlof different parameters.
Instrumentation is defined as "the artand science of measurement and control".
Measuring is used to monitor a process oroperation
Instrumentation is a branch of engineeringthat deals with the measurement and controlof different parameters.
Instrumentation is defined as "the artand science of measurement and control".
Measuring is used to monitor a process oroperation
UNIT 1
Objectives ofEngineering Measurement
Objectives ofEngineering Measurement
Objectives At the end of this Unit
Basic measuring systemPerformance characteristics of
instrumentsErrors in measurementUnits-Dimensions Standards.Instrument calibration.
At the end of this Unit
Basic measuring systemPerformance characteristics of
instrumentsErrors in measurementUnits-Dimensions Standards.Instrument calibration.
Objectives Of Engineering Measurements
1. Measurements of system parameterinformation.
2. Automatic control of a system.
3. Simulation.
4. Experimental design.
5. To perform various manipulation.
6. Testing of materials and quality control.
7. Verification of scientific theories.
1. Measurements of system parameterinformation.
2. Automatic control of a system.
3. Simulation.
4. Experimental design.
5. To perform various manipulation.
6. Testing of materials and quality control.
7. Verification of scientific theories.
Basic Measuring System A measurement assigns a specific value to a
physical variable. The physical variable nowbecomes the measured variable.
A measurement system is a tool used to measurethe physical variable.
Methods of measurement can be classified in totwo
Direct methods Un known quantity is directly compared against a
standard Result is expressed as a numerical number
In direct methods In engineering application measurement systems
uses this methods
A measurement assigns a specific value to aphysical variable. The physical variable nowbecomes the measured variable.
A measurement system is a tool used to measurethe physical variable.
Methods of measurement can be classified in totwo
Direct methods Un known quantity is directly compared against a
standard Result is expressed as a numerical number
In direct methods In engineering application measurement systems
uses this methods
Simple measuring systemSignal conditioningelement
Data transelement
Data processingelement
Primary sensingelement
Transducer
Data display
Transducer
Data recording
Basic Measuring System Four Parts of Measurement System
Sensor-Transducer Stage Signal Conditioning Stage Output Stage
Sensor The sensor is a physical element that uses some
natural phenomenon to sense the variable beingmeasured.
The transducer changes this sensed informationinto a detectable signal form (electrical,mechanical, optical, etc.)
A Transducer is a device which converts one formof energy into some other form of energy
It is also known as 'Pickup Element'.
The sensor is a physical element that uses somenatural phenomenon to sense the variable beingmeasured.
The transducer changes this sensed informationinto a detectable signal form (electrical,mechanical, optical, etc.)
A Transducer is a device which converts one formof energy into some other form of energy
It is also known as 'Pickup Element'.
Sensor Mainly Transducers can be classified into two types on
the basis of power supply required Active Transducers Passive Transducers. Active transducers are those which does not requires
external power supply for their operation. For example: Photo Voltage Cell, Piezo Electric Crystal,
Generator etc. Passive Transducers: Passive Transducers are those
transducers which requires external power supply fortheir operation.
For Example: Resistive, Inductive and CapacitiveTransducers.
Mainly Transducers can be classified into two types onthe basis of power supply required
Active Transducers Passive Transducers. Active transducers are those which does not requires
external power supply for their operation. For example: Photo Voltage Cell, Piezo Electric Crystal,
Generator etc. Passive Transducers: Passive Transducers are those
transducers which requires external power supply fortheir operation.
For Example: Resistive, Inductive and CapacitiveTransducers.
Signal Conditioner
Its role comes into play when the output oftransducer or primary sensing element is verylow. It is used to amplify or modify the incomingsignal from transducer according to outputrequirement.
When noise is present in signal, filters need to beused to eliminate it.
If the processor operates only on digital signal,A/D and D/A converters must be used at theinput and output of the processor
In other words Signal Conditioning is done toimprove the quality of output of measurementsystem.
Its role comes into play when the output oftransducer or primary sensing element is verylow. It is used to amplify or modify the incomingsignal from transducer according to outputrequirement.
When noise is present in signal, filters need to beused to eliminate it.
If the processor operates only on digital signal,A/D and D/A converters must be used at theinput and output of the processor
In other words Signal Conditioning is done toimprove the quality of output of measurementsystem.
Signal Conditioner This optional intermediate stage can be used to
increase
The magnitude of the signal throughamplification,
Remove portions of the signal through somefiltering technique,
Provide mechanical or optical linkage betweenthe transducer and the output range.
This optional intermediate stage can be used toincrease
The magnitude of the signal throughamplification,
Remove portions of the signal through somefiltering technique,
Provide mechanical or optical linkage betweenthe transducer and the output range.
O/P stage The output unit of a measurement system is
consists of a display and storage unit
It is used to display or analyze the final outputof the measurement system.
The examples of Output unit can be anyoutput device like CRO (Cathode RayOscilloscope) or XY recorder.
The output unit of a measurement system isconsists of a display and storage unit
It is used to display or analyze the final outputof the measurement system.
The examples of Output unit can be anyoutput device like CRO (Cathode RayOscilloscope) or XY recorder.
ComparisonDigital Signal Analog Signal Data Storage can be
easily done Processing of digital
information is very easy Will not interfere with
other signals, so lessaffected with Noise. Datatransmission quality isgood
Repeaters are requiredfor long distancecommunication
Difficult to store thesignal/information
Processing of signal isdifficult
Will interfere with othersignals, so affected withnoise. Transmissionquality is comparativelypoor
Repeaters are notrequired
Data Storage can beeasily done
Processing of digitalinformation is very easy
Will not interfere withother signals, so lessaffected with Noise. Datatransmission quality isgood
Repeaters are requiredfor long distancecommunication
Difficult to store thesignal/information
Processing of signal isdifficult
Will interfere with othersignals, so affected withnoise. Transmissionquality is comparativelypoor
Repeaters are notrequired
Performance characteristics ofinstruments
JOBY JOHN 15
Performance characteristics ofinstruments
Performance characteristics of instruments
A knowledge of the performancecharacteristics of an instrument is essential forselecting the most suitable instrument forspecific measuring jobs.
Performance characteristics of an instrumentare mainly divided into two.
Static characteristics Dynamic characteristics
A knowledge of the performancecharacteristics of an instrument is essential forselecting the most suitable instrument forspecific measuring jobs.
Performance characteristics of an instrumentare mainly divided into two.
Static characteristics Dynamic characteristics
STATIC CHARACTERISTICS
The set of criteria defined for the instrumentwhich are used to measure the quantities thatare varying slowly with time or constant is calledstatic characteristics.
OR The static characteristics of an instrument are
considered for instruments which are usedto measure an unvarying process condition.
Some criteria will be set to for the measurementof quantities that are either constant or varyslowly is called static characteristics
The set of criteria defined for the instrumentwhich are used to measure the quantities thatare varying slowly with time or constant is calledstatic characteristics.
OR The static characteristics of an instrument are
considered for instruments which are usedto measure an unvarying process condition.
Some criteria will be set to for the measurementof qua
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