ENGINEERING MEASUREMENTS Prof. Emin Korkut

SYLLABUS Principles of engineering measurements Statistical methods in measurements Measurement errors, calibration, signal conditioning, similarity, displacement, pressure, flow, speed, acceleration, liquid level, strain, force, temperature measurements Flow visualisation techniques Dynamometer principles Computer aided data acquisition Digital signal analysis Applied measurement project.

Lecture notes may be found at: http://www.gidb.itu.edu.tr/staff/emin/ or http://ninova.itu.edu.tr/Ders/2309/Sinif/7337

Planning of Engineering Measurements (Laboratory Projects) Ideal engineering measurement (laboratory project) should be entirely planned by the student and may include: objective method organisation of personnel analysis of results

Objectives of Engineering Measurements General objectives of this course are to prepare students to undertake later original projects in research and design and to provide some background for assignments he/she may expect as a junior engineer in industry.

Principles of Engineering Measurements (Basic Concepts) Definition of terms Calibration Standards Dimensions and units Generalised measurement system Basic concepts in dynamic measurements System response

i- Definition of Terms (Week2) Readability: This term indicates the closeness with which the scale of the instrument may be read: an instrument with a 10 scale would have a higher readability than an instrument with a 5 scale. For an instrument with a digital readout this term have a little meaning. In this case display of the instrument is important. Sensitivity: Ratio of the linear movement of the pointer on an analog instrument to the change in the measured variable causing this motion. For example, a 1-mV recorder might have a 25-cm scale length. Its sensitivity would be 25 cm/mV, assuming that the measurements was linear. Hysterisis: if an instrument displays a difference in readings one talks about hysterisis, which may be the result of mechanical friction, magnetic effects, elastic deformation or thermal effects.

i- Definition of Terms Accuracy: of an instrument indicates the deviation of the reading from a known input. Accuracy is frequently expressed as a percentage of full-scale reading, so that a 100 kPa pressure transducer having an accuracy of 1 percent would be accurate +-1 kPa over the entire range of the transducer. Precission: This term indicates the ability of an instrument to reproduce a certain reading with a given accuracy. 8