This book offers a relatively non- mathematical, real-world look at the design and operation of the complex measurement systems used in the experimental mechanics testing business where the over-arching requirement is test data that is valid beyond the question of a doubt, delivered on time, and economically affordable. It tells engineers what they need to know to survive on a daily basis in such test laboratories in today's high pressure, competitive and leveraged, cost driven, process-oriented test world. Explains the 10 crucial technical issues that must be understood and under control at all times if effective and perceptive measurements are to be made on a daily basis in the test laboratory. Also discusses a working philosophy, responsibility and engineering ethics, and management of the measurements activity. Features, here for the first time, The Measurement Contract, a definition of who owes what to whom when working in a really effective test laboratory. For any and all engineers and engineering managers responsible for the timely delivery of demonstrably valid test data in testing laboratories or whose organizations product quality depends on that testing.