Chapter 1 Introduction to ME 344 Instrumentation and Measurements Chap 1_ME344_Instrumentation & Measurements INSTRUMENTATION and MEASUREMENTS (ME344) Zakarya ZYADA, PhD F48, B16, Faculty of Engineering Taibah University E-mail: zzyada2014@gmail.com Chap 1_ME344_Instrumentation & Measurements Importance • Importance: This course is important for any Mechanical Engineering graduates, especially who will be concerned with: • Measurements, • Control, • Mechatronics, and • System Integration from the point of view of construction, maintenance, or design. Chap 1_ME344_Instrumentation & Measurements Importance • Importance: This course is important for any Mechanical Engineering graduates, especially who will be concerned with: • Measurements, • Control, • Mechatronics, and • System Integration from the point of view of construction, maintenance, or design. Chap 1_ME344_Instrumentation & Measurements In view of control System Video Parallel Link Manipulator Control Chap 1_ME344_Instrumentation & Measurements Intended Learning Outcomes Knowledge 1. define the principles of measurement methods, and basic measurement concept 2. explain the behavior of measurement system, errors types, calibration standards, static and dynamic signal characteristics, 3. Define analog and digital components in measurements system. 4. List sensors used for measuring different quantities: motion and dimensional measurement, force, torque, shaft power, pressure, strain , flow measurement, temperature and Heat-Flux Measurement 5. use common measuring instruments used by engineers Chap 1_ME344_Instrumentation & Measurements Intended Learning Outcomes Cognitive Skills 1. design and conduct experiments for measuring basic electrical and specific mechanical variables 2. Select appropriate sensors used for measuring different quantities: motion and dimensional measurement, force, torque, shaft power, pressure, strain , flow measurement, temperature and Heat-Flux Measurement 3. build simple data acquisition system using sensor, ready to use boards and modules. PC equipped with data acquisition software Chap 1_ME344_Instrumentation & Measurements Intended Learning Outcomes Interpersonal Skills & Responsibility 1. Analyze, interpret, and present experimental data using appropriate, meaningful and representative method. Communication, Information Technology, Numerical 1. report measurement in complete format including uncertainty level and associate probability 2. Apply probability and statistical techniques to analyze the measurements data 3. Perform uncertainty analysis to measured data. Chap 1_ME344_Instrumentation & Measurements Contents - 1 • General • Basic Concept of Measurement Methods, including general components , (3 hrs) • Behavior of measurement system, errors types, calibration and standards, (3 hrs) • Static and Dynamic Characteristics of Signals, (3 hrs) • Measurement System Behavior,(3 hrs) • Probability and Statistics for Engineering Measurements, (2 hrs) • Uncertainty Analysis, (2 hrs) • Sensors • Basic analog and digital electrical measurements, (2 hrs) • Motion and Dimensional Measurement, (2 hrs) • Force, Torque, and Shaft Power Measurement (2 hrs) • Pressure and strain Measurement ,(2 hrs) • Flow Measurement , (2 hrs) • Temperature and Heat-Flux Measurement (2 hrs) Chap 1_ME344_Instrumentation & Measurements Contents - 2 • Lab session • LabVIEW Programming: Introduction • LabVIEW Programming: Modular Programming • LabVIEW Programming: Repetition and Loop • LabVIEW Programming: Arrays • LabVIEW Programming: Clusters • LabVIEW Programming: Plotting data • Sensor set up, hardware connection, software configuration and sampling using lab assembled data acquisition for temperature. • Conventional fluid flow rate and pressure measurements. • Strain measurements • Pressure measurements • Motion and Dimensional Measurement • Force, Torque, and Shaft Power Measurement Chap 1_ME344_Instrumentation & Measurements Assessment • • • • • • • • • • • Quiz 1: Quiz 2: Midterm Test 1: Quiz 3: Quiz 4: Midterm Test 2: Quiz 5: Lab Reports Course project Final Exam: Total W3 W5 W6 W7 W9 W10 W11 W 4, 8, 12 W16 2% 2% 10% 2% 2% 10% 2% 20% 10% 40% 100% Chap 1_ME344_Instrumentation & Measurements Text book References Text book • R. S. Figliola, D.E.Beasley, Theory and Design for Mechanical Measurements, 6thed., John Wiley & Sons, Inc., 2015 (or later) References: • Measurement and Instrumentation: Theory and application, Alan S. Morris and Reza Langari, Elsevier, 2012. • 2. Experimental Methods for Engineers, by Holman, J. P., McGraw Hill, 2011 • Process Control Instrumentation Technology, Curtis D. Johnson, Prentice-Hall, 2009, and others Chap 1_ME344_Instrumentation & Measurements Introduction to measurement and instrumentation, Measurement standards and units, instrumentation system Chap 1_ME344_Instrumentation & Measurements Introduction to Measurement and Instrumentation By the end of this lecture, you should be able to reply: • What is measurement? • What is an instrumentation system? • What are the measurement standards and units? Chap 1_ME344_Instrumentation & Measurements What is measurement? • Measurement is “a set of operations having the object of determining the value of a quantity”, (International Vocabulary of Basic and General Terms in Metrology (VIM)). • A measurement is an act of assigning a specific value of a physical variable. The physical variable is the measured variable. Measurement systems: for what purpose? • • • • To measure physical variable, mass, temperature, pressure, voltage, …etc. To locate things or events, the centre of an earthquake, a landmine,…etc To discriminate and count objects, red blood cells, car flow rate in streets Often, a part of a control system, “if you can measure it, you can control it” Chap 1_ME344_Instrumentation & Measurements What is an Instrument? • An instrument is a device that transforms a physical variable of interest (measurand) into a form that is suitable for recording (measurement) Simple instrument model Example of an instrument: ruler • Measurand: length, • Measurement: number of units (meters, inches, …etc.) that represent the length. Chap 1_ME344_Instrumentation & Measurements Instrument System Stages Physical variable (measurand) Signal variable Sensor stage Measurement Signal conditioning stage Output Stage Process Observable variable : • need not necessarily be the measurand, but related to it in some way. Example: • Measurand: mass • Measured variable: force Signal variable: • Can be manipulated in a transmission system • Electrical: like current • Mechanical: like pressure Measurement : observed output • Displayed, • Recorded, • Transmitted to other parts, like in control Chap 1_ME344_Instrumentation & Measurements Sensor Physical variable input Sensor Sensor is a an element that performs initial measurement (employing some natural phenomena) and energy conversion. (other definitions are also available) Phenomena: deflection of a very small cantilever beam near the surface by atomic forces Chap 1_ME344_Instrumentation & Measurements Signal variable output Signal conditioning Signal variable Signal conditioning stage Conditioned signal variable Optional: • Amplification: Changing signal amplitude • Filtering: removing some portions of the signal Chap 1_ME344_Instrumentation & Measurements Output Conditioned signal Output stage Measurement Conditioned signal A/D Measurement • Recorded, • displayed or • processed Computer D/A For control Dial Gauge, pressure Vibration measurement measurement Chap 1_ME344_Instrumentation & Measurements Need for measurement In industrial application, it is important for: • Monitoring and control of processes, • Improving the quality of products and efficiency of production, • Safety purposes. Chap 1_ME344_Instrumentation & Measurements Examples -1 Surface roughness measurement Transducer converts the sensed information into a signal variable Note: the term transducer is often used to refer to a packaged device which may contain sensor, transducer and even signal conditioning elements. Chap 1_ME344_Instrumentation & Measurements Examples-2 Accelerometer Oxygen Sensor Airflow Sensor CO Sensor Oil Pressure Chap 1_ME344_Instrumentation & Measurements Water Temperatur e Chap 1_ME344_Instrumentation & Measurements Chap 1_ME344_Instrumentation & Measurements Chap 1_ME344_Instrumentation & Measurements Examples -3 : biomedical Ultrasound Transducer Chap 1_ME344_Instrumentation & Measurements Spirometer: lung capacity ( records the amount of air and the rate of air that is breathed in and out over a specified period) Chap 1_ME344_Instrumentation & Measurements Chap 1_ME344_Instrumentation & Measurements Laser sensor Chap 1_ME344_Instrumentation & Measurements Photoelectric sensor - is a device used to detect the distance, absence, or presence of an object by using a light transmitter Chap 1_ME344_Instrumentation & Measurements Measurement system for control Physical variable Sensor & transducer stage Signal conditioning stage • Amplifier • Filter Process Actuator Control stage Chap 1_ME344_Instrumentation & Measurements Signal variable Measurement Output Stage Measurement Standards and Units Measuring system are composed of different elements and condition therefore it needs norms and standards 3 unit systems widely used-International System (SI), CGS System (derived from SI), English System Basic units - length, time, mass, temperature Derived units –area, volume, acceleration, force Chap 1_ME344_Instrumentation & Measurements International System of Units (SI) The SI is founded on seven SI base units for seven base quantities assumed to be mutually independent, as given in Table 1. SI base unit Base quantity Name Symbol length meter m mass kilogram kg time second s electric current ampere A thermodynamic temperature kelvin K amount of substance mole mol luminous intensity candela cd Chap 1_ME344_Instrumentation & Measurements Derived Units - defined in terms of the seven base quantities via a system of quantity equations. Examples are: SI base unit Name Derived units Symbol area square meter m2 volume m3 force cubic meter meter per second meter per second squared kg·m·s-2 pressure kg·m-1·s-2 Pa work kg·m2·s-2 Joule velocity acceleration Chap 1_ME344_Instrumentation & Measurements m/s m/s-2 N Metric Prefixes Appendix 1 Multiple SI prefix Symbol 1012 109 tera T giga G 106 mega M 103 kilo k 102 hecto h 10 deka da Chap 1_ME344_Instrumentation & Measurements Metric Prefixes Appendix 1 Multiple SI prefix Symbol 101 102 deci d centi c 103 milli m 106 micro 109 nano n 1012 pico p 1015 femto f 1018 atto a Chap 1_ME344_Instrumentation & Measurements Example -1 Express a pressure of p 2.1103 dyne/cm2in pascals. 1 Pa = 1 N/m2 . Solution: from Appendix 1, 1N dyne and 1 cm = 102 m 2 cm 1N p 2.1×10 dyne/cm 10 5 m 10 dyne p 210 N/m 2 210 Pa 2 3 2 Example-2 Express 6.00 feet in meters 1 in.= 0.0254 m and 12 in. = 1ft m in 6 ft = 6 ft 12 0.0254 =1.83m in ft Sol: from table A.1.2, Chap 1_ME344_Instrumentation & Measurements Self-assesment Identify the elements for the pressure measurement system i.e. : transducer, signal conditioner, display POINTER Chap 1_ME344_Instrumentation & Measurements
