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Reliable test results

To keep up with fast-paced technological advances, developers and engineers are continuously trying to push the boundaries of physics to develop new and improved materials. At the same time, globalization is leading to international supply chains and spatial separation of research and production sites. Consequently, it is imperative for quality assurance and R&D that test results be accurate, repeatable, reproducible and traceable – in one word, they have to be reliable.

Definition of reliable test results

Reliable test results are a fundamental, highly relevant topic in materials testing—regardless of whether testing is standard or custom-configured. With each materials and components test we ask the same questions:

  • Is the value obtained truly accurate?
  • Are the results repeatable?
  • Are these results comparable to other measurements?
  • Is it possible to determine who, when, how, and what happened?
  • Finally, does the measuring equipment meet the required standards and specifications?

ZwickRoell, together with its machine and software solutions, stands for accuracy, repeatability and reproducibility and for seamless result traceability.

Reliable Test Results - Accuracy


Measurements that are precise and correct, are accurate

  • Precision is the closeness of two or more test results to each other, under predefined conditions. This means: Individual test results that are close together are precise, while individual test results that are not close to each other are not precise.
  • Correctness describes the closeness of the average value of the individual test results and a reference value. This means: The result is correct if the average value of the individual test results is close to the reference value. It is not correct if there is a big difference between average value and reference value.
  • Individual test results that are close together and whose average value is close to the reference value are accurate.
Reliable Test Results - Repeatability


Repeatability is precision under repeating conditions

  • The same measurement procedure
  • The same machine operator
  • The same testing equipment
  • The same location
  • And the same test conditions
  • The repetition of measurements in short time intervals is the only variable factor
Reliable Test Results - Reproducibility


Reproducibility is precision under reproducible conditions

  • The same measurement procedure
  • Similar measuring instruments
  • Generally at different locations
  • With several operators
  • Under changing test conditions
  • Such as the performance of measurements over longer periods of time
Reliable Test Results - Traceability


Traceability refers to comprehensive and complete documentation of a test result

  • How the test result was determined
  • Under what conditions
  • When it was determined
  • Were was the measurement performed
  • And by whom

Video on reliable test results

Reliable test results are a fundamental and hot topic in materials testing.

Our promise of reliability

When our customers purchase a ZwickRoell testing machine, they not only obtain a machine with the highest level of quality, they also gain a partner with more than 160 experience in materials and components testing. Our goal is to make sure our customers achieve the most reliable test results possible. That is what drives us every day:

  • high-quality production “Made by ZwickRoell”
  • Intuitive software with integrated standards and test methods
  • Fast and professional support for calibrations, customizing and maintenance all over the world