Understanding 'As Found' And 'As Left' Calibration Data And Its Importance

April 01, 2022

Accuracy and reliability are of great importance for lab equipment. For this reason, lab equipment must be calibrated on a regular basis — anywhere from monthly to yearly — in order to remain in spec, accurate and safe. The concepts of “as found” and “as left” calibration data play a major role in the calibration process, and we will explore those types of data here.

What Does ‘As Found’ and ‘As Left’ Calibration Data Entail?

“As found” and “as left” involves two types of calibration data:

  • As found data
  • As left data

Each type of data is different: It is collected at different times, signifies different things and is used for different purposes. Let’s take a closer look at exactly what as found and as left data are.

What Is As Found Data?

As found data represents the state of the equipment when it is received by calibration personnel, before any calibrations, adjustments or repairs occur. It is typically collected through performance testing as compared against a standardized set of results.

As found data fulfills several functions:

  • It indicates whether calibration or adjustment is needed
  • It provides quality assurance and validation for previous processes
  • It illustrates whether the equipment has been in spec while in use
  • It creates a historical record that can be used to create more effective calibration schedules

This data will typically be listed on calibration certificates as an indication of calibration work completed.

What Is As Left Data?

As left data represents equipment performance and accuracy after any necessary repairs, adjustments, and other calibration steps have occurred. As left data is used to:

  • Validate that the equipment has been calibrated and that it is within spec
  • Benchmark equipment performance for future processes
  • Illustrate the scope of work completed in the calibration process

As left data will also be listed on calibration data certificates. The term “found left data” indicates that the as found and as left measurements are identical — in other words, that no calibration or adjustment was required or carried out.

As you can see, these two terms are related but not interchangeable. They represent different stages of the calibration process (“as found” for data collected prior to calibration and “as left” for data collected after calibration) and have complementary but different uses. One thing that they have in common is their necessity for accurate equipment calibration in laboratory settings.

Technical Safety Services offers a broad range of laboratory equipment calibration services, including collection and certification of as found and as left data. We are experts not only in calibration processes, but also in the documentation that you need to keep your facility operating and keep your records copacetic.

To learn more about how we can help you, contact us today.

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