AMTMA Perspectives: Calibration reports - How much information must be reported?

In the first column from the American Measuring Tool Manufacturers Association (AMTMA) membership, the author digs into the standards to clarify what should be included in calibration reports.

By Hilliard Cox, Frank J. Cox Sales Ltd.

Calibration laboratories across North America are being asked to provide additional information in their calibration reports — more than is required in the relevant standards.

Typical of these requests is a demand that reports show the last calibration date of the equipment and masters used for the work and their next calibration date. In many cases, those making the requests insist that "the specifications" require this information to be reported.

There are three recognized specifications dealing with calibration in general use on a worldwide basis. They are:

• ISO Guide 25 (now being replaced by ISO 17025)
  
• ANSI/NCSL Z 540-1
  
• ISO 10012

What the Specifications Say
After checking the specifications, this is what we found. Guide 25 & Z 540 specifications deal exclusively with testing and calibration labs that do work for other parties, while ISO 10012 specifications are primarily for companies who intend doing all or part of their own calibration work in-house.

All three of these specifications note the need to record the dates equipment and reference standards were last calibrated and when they are next due for calibration. However: They all require this information to become part of the laboratory's equipment record, rather than a calibration report that may be issued by an outside lab.

This requirement is noted in Section 8 of Guide 25, which deals with "Equipment and Reference Materials" — not reports. Sub-section 8.4 notes the requirement in paragraph d "where applicable." ISO 10012 notes the same requirement for the same purpose in section 4.8. In every case, these requirements deal with the historical record of equipment and masters used for calibration and make no reference to such information being placed in a calibration report.

Calibration reports are referenced in Guide 25, which lists the information a lab must report in section 13. This extra information is not a listed requirement. Similarly, Z 540 in section 13 also lists what must be reported and there is no requirement for this information. ISO 10012 doesn't list any requirement for what must be included in reports because it primarily covers in-house calibration, where the information is placed on the equipment record.

The reason such information isn't a requirement for calibration reports issued by outside laboratories working to Guide 25 or Z 540 is that the information is of little or no use unless the recipient reviews the lab's procedures and historical data to determine if the dates are appropriate. This type of evaluation is best performed by experts from laboratory-accrediting agencies who make it part of their on-site assessments.

Occasionally, an auditor will insist that this information is provided on calibration reports as part of his or her organization's policy. This becomes a special requirement not covered by the specifications that labs are accredited to. These special requests should be made in writing to the lab and may be subject to extra cost for the additional information.

The primary reasons for the specifications referenced here is to ensure uniformity in the qualifications and reporting by calibration labs. If everyone wants different information on the calibration reports they receive, the benefit of having the specification is lost. In addition, the value of having a lab accredited to Guide 25, for example, also is lost if most reports have special information requirements (some of which may mean different calibration procedures as well).

As AMTMA labs are accredited to Guide 25, they will attempt to provide whatever information our customers require in their reports. To do so, however, may change the costs involved when a "standard" report is no longer issued to a recognized specification.

It's important for companies and customers to obtain original copies of the relevant specifications — rather than interpretations — so they will have an accurate description of what the standard is compared to what may be someone else's "policy." Then companies can weigh the benefits — if any — of requests made for additional information.

About the Author
Hilliard Cox is part owner and president of Frank J. Cox Sales Ltd. (Brampton, Ontario), which sells precision gages and measuring instruments. The company also owns Hilco Gauge Mfg. Co., Ltd., which manufactures threaded and plain gages as well as gaging fixtures and dimensional masters. The firm also maintains the Canadian Central Gauge Laboratory, an A2LA-accredited calibration facility.

Cox is past-president of the AMTMA and currently serves as chairman of the AMTMA committee for quality manuals, specifications, and laboratory accreditation. He created and co-authored the AMTMA handbook, "Searching for Zero," which outlines the technology required to calibrate high accuracy masters and gages.

He is a member of the Canadian Standards Association Metrology Committee, the Canadian ISO/TC213 committee dealing with dimensional metrology, and the Society of Manufacturing Engineers.

Cox designed the Thread Trend 3-roll thread measuring system and was the design coordinator of a benchtop optical comparator that's produced in England and marketed internationally. He also designed and monitored the construction of four successive high-level metrology laboratories for use by his company. He is a design consultant for dimensional metrology instruments as well as a contract metrology consultant.

He can be reached during regular business hours at 905-457-9190.
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