df251ed0-77b9-48b6-9680-3b0b79303997
TRANSCRIPT
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Introduction toMeasurement Systems
References: Measurement Systems
Application and Design 5th EditionErnest O.Doebelin Department of Mechanical Engineering The
Ohio State UniversityPublished by McGraw-Hill
New York, USA. 2004
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Measurement is the operation of
determining the value of a quantity.
Measurement/instrumentation system is themeans used to carry out a measurement.
The field of measurements is rapidly
changing where new Standards,Sensors ,Requirements andMeasurement
systemsare continually being devised
Measurement and Measurement System
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Measurementis an act of assigning a specific value
to a physical variable detected by asensor.
A Measurement sys temincludes all the components
necessary for producing a measurement.
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Measurement system
Measures a physical quantity
Displays result to an operator
and/or
Records result
and/or
Transmits to another system (e.g. a
control system)
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The base of Measurement objectives is from
common language for various systems.
Process _______ Qualitity(Variable)
(event)
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Purpose of measurement system:
MONITORING OF PROCESSES ANDOPERATIONS
CONTROL OF PROCESSES AND
OPERATIONS If you can not measure it,you can not control it .
EXPERIMENTAL ENGINEERING
ANALYSIS COMPUTER-AIDED MACHINES AND
PROCESSES
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Measured objects
Industrial process
Moving objects
One 600,000KW thermal power machine groups:About 800 measurement pointshundreds of instruments
Examples:
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Automobile Electronics
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Normal Car:40-50 sensors
Luxury Car:about 200 sensors
Oil
sensor
Oxygen
sensor
Fuel level
Accelerometer
Seat belt tension
Passenger Occupancy
Wheel speed
Tire pressure monitorRadar sensor
Rain sensor
Parking sensor
Indoor/outdoortemperature sensors
GPS
Water coolant
temperature
Tachometer
SpeedometerOdometer
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ShenZhou Aircraft:near 200 sets of instruments
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Main subjects and topics
Principles of measurement:
Laws and phenomena of natural science:Physics, Chemistry, Biology etc.
for measured variable and measurement methodsone to many
new principles for new sensors developmentMeasurement methods and instruments and equipmentMeasurement engineering
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Measurement Applications
1. Monitoring of processes and operations.
2. Control of processes and operations.3. Experimental engineering analysis
4. Computer-aided machines and processes
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Professional Division:
Metrology():standard, metrical transitivity()
Instrument manufacture
Instrument engineering
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Real-Time Robust
Economy
For Efficiency, Safety, Environmental protection
The eye for production and supervision
Display check, supervision, control and record
New measurement points needed
Multifunctional instrumentation needed
Engineering Measurement
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ScientificMeasurementor Laboratory measurement
Measured objects: studied process orobjects
High precisionspecial variablecombined variables
Display and record
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New trends and applications
Digital instrumentIntelligent or smart instrument
Miniaturized system or micro-system
Networked
Virtual instrument
Multifunctional
Software instrument
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Class Overview /Objectives
Define generalized configurations and descriptions of
measuring systems.
Describe and perform static calibration of numerous
types of measurement devices.
Select and/or design measurement systems to meet
performance specifications.
Describe the principles and characteristics of the most
common measurement systems for the measurement of
motion, forces and torques, pressure, flow, and
temperature.
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Restated Course Objectives
All measurements have an associated uncertainty (which is
not always known in advance). Engineers / scientists need
to know how to assess this uncertainty.
All instruments have a finite range of application. It isimportant to select the best instrument for the task at
hand. (Sensitivity, Bandwidth, Cost, Reliability)
Most real measurements involve determination of multiple
variables, each with its own associated uncertainty.
How do we assess the TOTAL measurement error?
How do we assess the probability of component failure?
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Reference Textbook
Part 1
Part 2
No Part 3
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Summary
Measurement and Measurement systems
Engineering Measurement and Laboratorymeasurement
New Measurement Systems
Courses Objectives
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Assignment
(
Review Ch1 (P3-10)