Ch1

1. Engineering Measurement
Dr. Momen Qasaimeh

2. Course syllabus

3. Course syllabus
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

4. Course syllabus
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

5. Course syllabus
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

6. Introduction
Objective: To introduce electronic instrumentation systems to make accurate and meaningful
measurements of Mechanical and Thermal quantities.
• Measurement provides quantitative information on the actual state of the physical variables and
processes that otherwise could only be estimated.
• Measurements can be performed using one of the following:
1. Mechanical systems: rarely used, simple, less accurate. e.g dial gauge.
2. Electrical systems: widely used, more accurate, and provide electrical
output signal. e.g. strain gauge, thermocouple.
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

7. The Process of Measurement:
An Overview
INTRODUCTION
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

8. The Process of Measurement:
An Overview
THE SIGNIFICANCE OF MECHANICAL MEASUREMENT
All mechanical design of any complexity involves three
elements:
experience, the rational element, and the experimental element.
• The experience is based on previous knowledge and on an
engineer's common sense.
• The rational element relies on quantitative engineering
principles.
• The experimental element is based on measurement.
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

9. The Process of Measurement:
An Overview
THE SIGNIFICANCE OF MECHANICAL MEASUREMENT
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

10. The Process of Measurement:
An Overview
Examples OF MECHANICAL MEASUREMENT
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

11. The Process of Measurement:
An Overview
Examples OF MECHANICAL MEASUREMENT
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

12. The Process of Measurement:
An Overview
Component of a general measurement system
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

13. The Process of Measurement:
An Overview
Sensor and transducer
A sensor detects a physical, chemical or biological quantity and converts the data it receives through this
detection into an electrical signal.
A transducer is an electronic device that converts energy from one form to another. Common examples
include microphones, loudspeakers, thermometers, position and pressure sensors, and antenna.
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

14. The Process of Measurement:
An Overview
FUNDAMENTAL METHODS OF MEASUREMENT
• Direct comparison with either a primary or a secondary standard
• Indirect comparison through the use of a calibrated system.
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

15. The Process of Measurement:
An Overview
THE GENERALIZED MEASURING SYSTEM
• Stage 1. A detection-transduction, or sensor-transducer, stage.
• Stage 2. An intermediate stage, which we shall call the signal-conditioning stage.
• Stage 3. A terminating, or readout-recording, stage.
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

16. The Process of Measurement:
An Overview
THE GENERALIZED MEASURING SYSTEM
• Stage 1. A detection-transduction, or sensor-transducer, stage.
To detect or to sense the measurand. At the same time, this stage should be insensitive to every other
possible input.
Unwanted sensitivity is a measuring error, called noise when it varies rapidly and drift when it varies
very slowly.
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

17. The Process of Measurement:
An Overview
THE GENERALIZED MEASURING SYSTEM
• Stage 2. An intermediate stage, which we shall call the signal-conditioning stage.
The purpose of the second stage of the general system is to modify the transduced information so that it is
acceptable to the third, or terminating, stage.
In addition, it may perform one or more basic operations, such as selective filtering to remove noise, integration,
differentiation or telemetering as may be required
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

18. The Process of Measurement:
An Overview
THE GENERALIZED MEASURING SYSTEM
• Stage 3. A terminating, or readout-recording, stage.
Provides the information sought in a form comprehensible to one of the human senses or to a controller.
The output is presented in on of the following forms:
1. As a relative displacement.
2. In digital form
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

19. The Process of Measurement:
An Overview
TYPES OF INPUT QUANTITIES
• Time Dependence:
1. Static: constant in time
2. Dynamic-varying in time
(a) Steady-state periodic
(b) Nonrepetitive or transient
i. Single pulse or aperiodic
ii. Continuing or random
• Analog and Digital Signals
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

20. The Process of
Measurement:
An Overview
TYPES OF INPUT
QUANTITIES
• Analog and
Digital Signals
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

21. The Process of Measurement:
An Overview
MEASUREMENT STANDARDS AND CALIBRATION
• measurement is a process of comparison.
• So, we must employ a basis of comparison-standardized units.
• At some point during the preparation of a measuring system, known magnitudes of the input quantity must be
fed into the sensor-transducer, and the system's output behavior· must be observed.
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

22. The Process of Measurement:
An Overview
MEASUREMENT STANDARDS AND CALIBRATION
•
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

23. The Process of Measurement:
An Overview
CALIBRATION
• Single-point calibration: output = constant x input
• Multipoint calibrations are used, wherein a number of different input values are applied.
• Dynamic calibration: made by using a time-dependent input standard.
• Static calibration, using a constant input signal.
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

24. The Process of Measurement:
An Overview
CALIBRATION
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

25. The Process of Measurement:
An Overview
Measurements, BIPM, SI, traceability, calibration and standards
Mechanical Measurements
Sixth Edition
Thomas G. Beckwith Dr. Momen Qasaimeh

26. The End of Chapter 1