Description

This three-day course is for engineers, scientists, and managers who must use systems to understand experimental test measurements on a daily basis. How do you know your test measurements are valid? Since NIST traceability actually guarantees little about your test data, how do you know? Could you prove validity to your customer? What is the right measurements solution for your testing requirements? Is it really as simple as the vendors say? What is your real cost of invalid, ambiguous data causing retest or, worst of all, hardware redesign?

Learn how to design, buy and operate effective automated measurement systems providing demonstrably valid test data, the first time.

Fundamental & underlying engineering principles governing the design and operation of effective automated systems are demonstrated experimentally.

The result? Skilled people running more effective testing programs generating unambiguous data, lowered design verification risk and cost, and delighted customers. Attendees receive course notes.

What You Will Learn:

How to guarantee your data.
How to set the crucial system transfer functions to assure valid data.
How to follow the rules for waveshape and spectral reproduction of data.
The twelve things you have to control before you can sample properly.
How to absolutely eliminate deadly aliasing.
How to identify and prevent 40% errors in 0.1% systems!
Foolproof automated methods for noise level identification and control.
How to operate successfully in the PC-based data acquisition system market.

Course Outline:

1. Basic Measurement Concepts. Fourteen real measurement horror stories and why they happened. Measurements or instrumentation? Data validity or data accuracy? Why you want less than 1/16th of the information from your system.
2. Measurement System Transfer Functions and Linearity. Frequency and phase responses — more complicated than most think. First, second and higher order systems. Single degree-of-freedom systems and damping. Output/input linearity.
3. Frequency Content or Wave Shape Reproduction? Rules for the reproduction of frequency content. Rules for the reproduction of wave shape. What price do you pay when you violate the rules? How can you recover?
4. Non-Self Generating Transducers. Load cells, strain gages, resistance temperature transducers, piezoresistive and servo transducers, etc. The basic transducer model. Proper techniques for system set-up and operation.
5. Wheatstone Bridge. The bridge as a computer. Bridge equations. Valid shunt calibration techniques and calculation. The three wire circuit. Up to ten wire circuits!
6. Self Generating Transducers. Piezoelectric transducers. “Charge” amplifiers and why they work. Thermoelectricity and thermocouples. The gradient approach to thermocouple temperature measurements.
7. The General Transducer Model and Noise. How all transducers and components really work. Bulletproof noise level hunting and documentation procedures. Differential systems and common mode performance. Noise/Identification/Reduction Methods.
8. Information Conversion. Carrier systems and why they work. Sinusoidal excitation. Pulse train excitation–zero based and zero centered. Real examples.
9. Frequency Analysis. Fourier spectra. Power or auto spectral density. Octave and one-third octave analyses. Shock response spectra–what do they really tell you?
10. Sampled Measurement Systems. The twelve things you must know before you sample. Nonsimultaneous or simultaneous sample and hold? Aliasing and undersampling errors and how to prevent them. What antialiasing filters should you use and why?
11. Data Validation Methodologies. How do you know your data is valid? How to use your software to answer the question.
12. Knowledge-Based System Design Principles. The highest level of system design. Operating effective measurement systems. World-class examples from the spacecraft dynamics, thermal, and quasi-static structural test worlds.
13. The Subject of Software. Commercial software. Commercial vs. in-house developed software. Where’s the risk?
14. The Crucial Stuff They Didn’t Teach You in College. The subjects of craft, skill, responsibility, and professionalism as they relate to test measurements.

Instructor(s):

Mr. Charles Wright is a Senior Engineering Specialist in the Environments, Test and Assessment Department, Engineering Technology Group of The Aerospace Corporation. He works in the areas of test measurements, environments, and methods, and assessments of test effectiveness from a cross program perspective. Mr. Wright came to The Aerospace Corporation in 2001 from Northrop Grumman Aerospace Systems. During his three plus decade career there, he lead and managed the provision of advanced test measurement engineering services for space system development, integration and test. He is the author of Applied Measurements Engineering (Prentice Hall, 1995), and100 test-related technical publications. He has taught this course on more than 100 occasions all over North America to clients from US and Government national laboratories and agencies, commercial companies and in academic settings. Mr. Wright has a BS Mechanical Engineering and MS Measurements Engineering from Arizona State University, and an MS in Systems Management from the University of Southern California.

Contact this instructor (please mention course name in the subject line)