Search the Elsmar Cove!
**Search ALL of** with DuckDuckGo Especially for content not in the forum
Such as files in the Cove "Members" Directory

How many signatures do we need on calibration certificates?


Involved In Discussions
Fellow standardization enthusiasts,
How many signatures do we need on calibration certificates? Is it alright to have two i.e. Lab Analyst and Lab Manager?

Bev D

Heretical Statistician
Staff member
Super Moderator
Why would you need more than one? What purpose does the lab manager’s signature serve?


Involved In Discussions
You only need as many as is required based on the expertise of those signing. I'm not aware of any standard that requires a specific number of signatures.

If you are being really very careful, a signature and a verifier is about as far as I would take anything to do with calibration.

John Broomfield

Staff member
Super Moderator
I’d be happy just to know the certificate was verified as being correct.

A signature may or may not indicate this.

So, it boils down to our confidence in the lab’s accreditation.
I believe that you have been looking for help regarding ISO 17025 requirements.
17025 says this about what they are looking for on a calibration certificate in section

o) identification of the person(s) authorizing the report;

A lot of labs also attempt to meet the older ANSI Z540 requirement, which is slightly different:
  • a signature and title, or an equivalent identification of the person(s) accepting responsibility for the content of the certificate or report (however produced),

The person is often the quality manager, but it is whoever is the person delegated the authority to determine that the calibration results being presented are correct and meet requirements.
Many labs also include the person performing the calibration as one of the persons responsible for the content of the results.
If you want to add more, there is no reason why you cannot. I have sen a few labs that have their certificates notarized! However, I would counsel against adding extra signatures - extra stuff can come back to bite you in a audit.
6.2.6 states that you shall authorize a person to authorize results, that is correct. That signature must be on the certificate.

But o) calls for "identification of the person(s) authorizing the report ", clearly showing that there can be more than one signatory.

John Broomfield

Staff member
Super Moderator
More than one person may authorize but neither needs to sign. Google images of calibration certs from accredited labs and you can see for yourself.
Top Bottom