Digital Data Acquisition

Course No. 196

(Course Outline shown below.)

For whom intended  This course is intended for laboratory and field test technicians and engineers.

Objectives  To help participants to understand basic mechanical and structural concepts and terminology. It is not an in-depth mechanical engineering course but rather a course aimed at individuals who require an intensive review of basic principals, without the assumption of any prior knowledge of the topic. The course is fast paced and as non-mathematical as possible.

Brief Course Description  The objective of the course is to provide participants with the knowledge required to specify, evaluate and use a wide variety of digital data acquisition systems in laboratory and field applications. Basic principles of sampling and digitizing theory are presented and reinforced with practical examples from everyday testing operations. Emphasis is placed on understanding the theoretical concepts through "mechanical feel" rather than mathematics.

Hardware discussions concentrate on performance capabilities and practical problems that arise in laboratory and field applications.

Heavy emphasis is placed on new technologies and system concepts that will be available in the near future. The aim is to prepare participants to design and procure state-of-the art systems that will satisfy their technical requirements efficiently and economically.

Literature describing the latest available hardware will be used as examples of good (and bad) practice. Particular emphasis will be placed on critical evaluation of commercially-available hardware and software systems.

The course is presented as a series of highly-interactive lecture/discussion sessions. Problems for individual and group solution are interspersed throughout the course to act as training aids and to evaluate class progress. Special-interest discussions are encouraged outside of the regular course sessions.

Demonstration programs written in LabView are used during the course to illustrate the concepts. These demonstrations are available for download, free of charge (see http://www.ttiedu.com/ddaa-articles.html#demos). Students are encouraged to download the demonstration programs prior to class, and install them on a laptop computer they can bring with them to class and use to follow along with the instructor when the demonstrations are presented.

Related Courses  When presented as an open course, Course 196 is usually included as the first three days of Course 194, Vibration and Shock Test Control Techniques (http://www.ttiedu.com/194cat.html). It also forms the first three days of Course 197-5, Digital Data Acquisition, Signal Processing and Analysis (http://www.ttiedu.com/197-5cat.html), which may be presented on-site, at your facility.

Certificate Programs   This course is required for TTi’s Dynamic Test Specialist (DTS) certificate program. It may be used as an elective for any other TTi Specialist certificate program (see http://www.ttiedu.com/certprog.html).

Prerequisites  Participants should have attended TTi’s course, Instrumentation for Test and Measurement (http://www.ttiedu.com/163cat.html), or some equivalent training program. A good understanding of the engineering problem to be analyzed is expected. An understanding of basic computer and data acquisition principles will be useful.

Text  Each student will receive a course workbook, including most of the viewgraphs used in the course presentation.

Course Hours, Certificate and CEUs  Open courses meet seven hours per day. Upcoming presentation dates can be found on our current open course schedule (http://www.ttiedu.com/schedule.html). Class hours/days for on-site courses can vary from 14-35 hours over 2-5 days as requested by our clients. Upon successful course completion, each participant receives a certificate of completion and one Continuing Education Unit (CEU) for every ten class hours.

Course Outline No. 196

• Overview of the Measurement Process — The System Approach
  • The role and function of digital data acquisition.
  • Testing and experiment types — what capabilities are required?
  • Accuracy, Dynamic Range, Headroom
• Basic Concepts
  • Basic calculations
  • The Fourier Transform as a "Black Box"
  • Data presentation in time and spectral domain
• Sampling and Digitization Theory
  • Data acquisition speed and accuracy/resolution considerations
  • Aliasing (download TTi’s Aliasing Demonstration program from http://www.ttiedu.com/ddaa-articles.html#demos)
  • Noise and other data corruption problems
• Data Acquisition Hardware
  • Signal Conditioning
  • Amplifiers
    • Common-mode rejection
    • — Transducer wiring practice
  • Anti-alias filters
    • Estimating aliasing errors for different filter types
    • Filter/Sample-rate tradeoffs
  • Sample-and-hold amplifiers
  • Multiplexers
  • Analog-to-digital converters
    • Flash, Successive-approximation, Multi-pass, Sigma-Delta, Integrating
• The Computer System
  • Candidate computer systems — tradeoffs
  • Interface concepts — speed, implementation ease and robustness
  • Data storage — speed, volume considerations
• Types of Digital Acquisition Systems
  • Applications, Special considerations, Performance and limitations of available system architectures
• Data Analysis
  • Engineering-Unit Conversions
  • Data Interpolation
  • Correction of Anti-Alias filter distortion
• Evaluating Data Acquisition Systems
  • Simple tests to evaluate system accuracy/capability
• Specifying a system
  • How do you specify a system to get what you want?
• Final Examination
• Award of Certificates for successful completion

For schedules, enrollment information and more, visit http://www.ttiedu.com.