MadgeTech Blog

What Is “As-Found” Data?

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When instruments are sent to MadgeTech for calibration, the certificates accompanying the returned devices contain detailed “As-Found” data. But what does “As-Found” mean and is it different from “As-Left” data?

As-Found Data

As-Found data, also known as “Before-Data” or “Received-Data,” refers to the measurement data recorded when testing an item in the exact condition in which it arrived at the calibration lab. This data gives MadgeTech calibration technicians clear understanding of how the data logger was performing at the user’s facility. If the As-Found data shows the device is not operating within its established specifications, maintenance is necessary.

Calibration technicians then make the adjustments, upgrades, or repairs needed depending on the situation. This data not only exhibits impartial evidence as to how well the logging device was performing within established calibration specifications during its applied use, but also validates the corrective processes implemented since its last calibration certification.

As-Left Data

Once service to the data logger is complete, its calibration data needs to be recorded again. This data is called “As-Left,” or “After-Data.” As-Left data functions as a clean bill of health, showing measurements within performance specifications. Quite literally, it is the calibration data from the device as it leaves MadgeTech. This set of data validates why a change to the logging device was initiated and checks that it is now within specification, assuring users of accuracy for the coming period of use.


With this process, it is understandable that many people initially question the need for meticulous As-Found data reporting. What is the point of effectively null data once it is replaced by As-Left data after necessary adjustments have been made? It comes down to the fact that As-Found data describes the device performance while monitoring data trends during a set period of time. Such information is indisputably vital to quality process management in any and all industry sectors. As-Found and As-Left data combine to enable quality managers and buyers to make informed decisions about testing procedures, tool purchases, and calibration schedules. This is why all MadgeTech calibration certificates include both As-Found and As-Left data.  

For more information about MadgeTech’s ISO 17025 accredited calibration services call us at (603) 456-2011 or email [email protected].

About MadgeTech Marketing:

Found in 1996, MadgeTech takes pride in maintaining our production process entirely out of our headquarters in Warner, New Hampshire. Proudly known as an industry expert, MadgeTech data logging solutions are sold in more than 100 countries around the world to the world’s most regulated industries, providing the validation needed for compliance and quality control.