The Technical Records in Calibration Documentation

with 12 Comments

Are you aware of the requirements to generate a calibration certificates?

One of the very first things to have during the start of any calibration activity is to prepare the necessary documents like calibration methods, forms, and work instructions in order to record and document the performed job order. These are the measurement related records.

And prior to this, we are instructed to execute any customer requirements and guided by the rules as per the standard document (ISO 17025 standard).

Recording as part of our documentation is not a new activity. I believe that most of you that are engaged in this technical field are doing some kind of documentation or recording of results as part of your daily job activity.

In this post, I will present with you the following:
1. technical records that we need during calibration,
2. the reason why we need to record calibration results,
3. what to include in the calibration technical record,
4. the right way to amend a record as per ISO 17025: 2017 and which is also applicable to ISO 9001:2015 calibration management.
5. the clause under ISO 17025:2017 and ISO 9001:2015 related to technical records

I also discuss the lists of calibration documents which include the form that we need to have in order to maintain compliance with the requirements of ISO 17025 Standards including ISO 9001:2015 calibration requirements.

The Need for Technical Documentation in Calibration

Are you familiar with the statement “If it is not recorded then it is not calibrated”?

I do not remember who wrote that (you can comment it below). Based on the quality standard today in every industry, the above statement is very true.

As per my experience, the majority of calibration activities consist of 60% documentation and only 40% calibration (the technical aspect). There is more work performed in documentation compared to executing the actual calibration of instruments

Below is also some guide questions why we need to “Have” and ‘’Maintain’’ documents (form) and Technical Records in Calibration Documentation requirements:

  • How can you accomplish your calibration execution thorough and faster?
  • Do you know exactly what to check or verify during calibration?
  • When performing calibration, do you sometimes forget other requirements of the procedure?
  • How do you know that you followed the requirements of your customer during calibration?
  • How can you repeat the same procedure all over again and avoid missing important calibration data?
  • If some problems during reporting or recording are encountered, how can you directly determine the person who performed the calibration?

Simple advice, if you are starting to enter this field and you do not want too much documentation as part of work, then this is not a job for you.

But of course, there are still some exceptions that depend on the design of your calibration process, but in general, this will apply (more so if you are performing under quality department)

Problems You Will Encounter If You Do Not Have Sufficient Calibration Records or Technical Records.

  1. If Calibration procedure is not recorded and standardize, anyone has its own way of doing things which will result in more inaccurate and inconsistent results
  2. Without calibration records, you will not have data to review for any mistakes and corrections that can be used for future improvements.
  3. No records mean no work done resulting in a non-compliance during an audit.
  4. You will face the issue of traceability in the documentation. There is no way to backtrack your results to correct any issue related to reported results.

Technical Records Requirements as per ISO 17025:2017

ISO 17025 is an International Standards design to promote confidence in the operation of Calibration and Testing Laboratories. Its requirements on calibration records under Clause 7.5, Technical Records, which states that:

7.5.1 The laboratory shall ensure that technical records for each laboratory activity contain the results, report and sufficient information to facilitate, if possible, identification of factors affecting the measurement result and its associated measurement uncertainty and enable the repetition of the laboratory activity under conditions as close as possible to the original.

The technical records shall include the date and the identity of personnel responsible for each laboratory activity and for checking data and results. Original observations, data, and calculations shall be recorded at the time they are made and shall be identifiable with the specific task.

What are these Results, Reports and Sufficient Information?

In order to repeat the procedure when required and to establish traceability, the contents of the records shall include below (at least)

  • Date of calibration or testing;
  • Identity of the personnel responsible for the record;
  • Description of the UUT/ UUC (Unit Under Test or Unit Under Calibration)
  • Description of the reference standard;
  • Environmental conditions;
  • The Test of Calibration Procedure used;
  • Original observations, data, and calculations;
  • Results like: as-found/as-left results, calibration,  and uncertainty results

Reporting of results follows the requirements of a calibration report or certificate and other required information.

>> please check out the complete requirements of calibration report  here in my other post: How to Properly Use and Interpret an ISO 17025 Calibration Certificate

If ever there is an amendment or  corrections to be made, Clause 7.5.2 states that, both the original and amended data and files shall be retained and must include:

  1. the date of alteration or amendments,
  2. an indication of the altered aspects or mistakes
  3. the personnel responsible for the alterations

This means that there should be no hard erasures, a cross-out/ strikethrough is enough to cover the mistakes then a signature with date and the correct term alongside the mistakes is enough.

when making corrections

What are the Benefits of Using Forms and Maintaining Calibration Technical Records?

It is obvious that we need to record as per requirement but the following are some  reasons why we need to create and maintain a technical record:

  1. This is the main reason under ISO 17025:
    1. Clause 7.5.1 states that “ to enable the repetition of the laboratory activity under conditions as close as possible to the original”.
    2. Clause 7.5.2 stated as, “ to ensure that amendments to technical records can be tracked to previous versions or to original observations”.

  2. Evidence that we perform the required calibration job as per the procedure.

  3. To make your calibration results traceable.
    This means that to backtrack the person who performs the calibration including other factors that have an effect on the work done. Related to number 6 below on Measurement Traceability.

  4. Evidence of conformance to the standards (ISO 17025 or ISO 9001 calibration requirements) and processes during audits. Technical records are used as an answer (or evidence) to most of the audit questions.

  5. Evidence that we follow the procedures or requirements completely through the data results that we record and report. Not all information is reported in the calibration report, therefore, this serves as our back-up.

  6. A requirement for the Standard ISO 9001:2015 under Monitoring and Measuring Resources
    • under clause which states that “The organization shall retain appropriate documented information as evidence of fitness for purpose of the monitoring and measurement resources”.
    • under clause on Measurement Traceability which states: “The organization shall determine if the validity of previous measurement results has been adversely affected when measuring equipment is found to be unfit for its intended purpose and shall take appropriate action as necessary.”

——— This means that:

a. We need to maintain technical records as evidence of documenting the valid results of our measurements during monitoring.

b. We need to maintain records in order to traceback any issues concerning the effect of measuring equipment found to be out of tolerance that is used on a certain product in order to take appropriate action. This is where we can review past results for validation purposes in case an issue related to the calibration or measurement process is suspected.

How Long Can We Retain Calibration Records?

One way to control records is to keep them for a designated period. The recommended retention period for technical records in calibration or testing is at least 4 years. Be sure that it is documented under the control of records procedure.

A longer storage period for calibration records is required because some records are needed during performance review or history of data to be used during quality control.

This is also a requirement of regulatory bodies that we need to follow.

What are the Necessary Forms and Records That We Always Need to Perform Calibration?

Please do not get confused about the differences between a form and a record. Forms and records are not the same. A form is a blank document designed to guide and make a specific activity more organize and mostly much faster. While a record is a filled-up form or a form where the required data is already written in the provided space.

Forms are always the best tool to use in documenting or recording your accomplished work. Forms should always be a part of every calibration procedure.

Having a form to fill up with will provide a better and faster flow of calibration execution. It is a calibration template that will guide and show you what to do next. Just fill in the blanks.

The following are a list of forms and records that we need to have while performing calibration:

  • Forms for recording Calibration data – we call it  Measurement Data Sheet (MDS) (others call it Measurement Data Result or worksheet) – below are its purpose:
    1. it contains all data recording of calibration results and observation –
    2. This will guide you on what information we need to record.
    3. It summarizes the calibration procedure to avoid missing out some requirements
    4. This serves as a draft for review and approval
Sample Measurement Data Sheet (MDS)

Check in this link other details of the Measurement Data Sheet (MDS)
  • Accomplished Forms or a record of Customer requirements (if available) – to determine the specific requirements of the customers
  • Manufacturer Manual – a guide for proper operation and a source for accuracy requirements for verification.
  • Uncertainty Budget Template – for easy calculation of measurement uncertainty.
  • Calibration report template – a form where the final output from the MDS will be reported and to be printed as the final calibration certificate.
  • Calibration report of the reference standard used – to determine the exact data for calculation of results.

In this time where technology are advancing, forms does not necessarily in a hard format or copy. Depending on the resources of the lab, forms can be in an electronic format.

Just remember, all these documents must be controlled in any way possible or monitored for any changes and distribution.


One of the requirements for every documentation and Standard is to maintain a record. I have discussed in this post the importance of maintaining technical records, what are the technical records in relation to calibration execution, the forms we need during calibration and the related clause about technical records according to ISO 17025:2017 and ISO 9001:2015.

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12 Responses

  1. Ich
    | Reply

    Thank you very much again sir Edwin for sharing a very important guidelines in this field of work.
    This is very important for me as starter in this field of work.

    • Hi Ich,
      Happy to know that you have learned something in this post.

      Thank you for reading. Any questions you have in mind that is related to my post, please do not hesitate to message me.

      Best Regards,

  2. Simon Watah
    | Reply

    Very nice indeed Edwin.Good information and facts.I appreciate the information, as a Technician from a developing country, having acquired most of my instrumentation and calibration skills from hands on experience I have learnt alot from this post
    Thank you

    • Hi Simon,
      I am glad that you have learned from this article. Learning by yourself is really a challenging tasks. I hope my other posts will be useful for you as well.
      I appreciate your valuable comment.

      Best regards,

  3. Erwen Bilo
    | Reply

    Thank you Sir @Edsponce for a very informative Blogs, I have seen several Calibration certificate in my present work, But I wonder why both the same ISO17025 accredited labs using different calibration method, let say for fluke digital multimeter ( one certificate, Cal method = Euramet Cg15, other one instead of cal method it mention cal procedure = SOP142..) is calibration method and cal procedure validated during the audit by Accrediting Body? thanks

    • Hi Sir Erwen,

      You are welcome.

      As per ISO 17025 under clause note, method and measurement procedure is the same so it is not a problem if they are being used interchangeably.
      When the laboratory is accredited by a respective Accreditation body, we are confident that the method or procedure that the cal lab is using are validated and accepted before use. You can verify in their ‘Scope of Accreditation’ if the calibration they performed is written in their scope (under range and parameter).

      One requirement of ISO 17025 about method validation is that, if the method used is non-standard, developed inside the lab, or standard method that is used outside its intended scope or modified, it needs to be validated.

      The difference in the procedure or method that you have seen is that Euramet Cg 15 is a standard method, Internationally accepted method in which the validation is already done by Euramet, where validation is not needed (unless used outside the intended scope or modified).

      The other procedure or method – SOP142 is either a developed or a modified method, in which validation should be done. They may have to use the Euramet Cg 15 as a reference or other standard method available.

      One thing you can do, which is a part of a cal lab’s customer service is that you can perform a lab visit or conduct a simple customer audit and verify the doubts in your mind.

      I hope this help,

      Thank you for reading my post.

  4. Randy Reyes
    | Reply

    Hi Sir, do we consider soft copy only (pdf) of calibration documents without signature as as calibration record?

    • Hi Randy,

      Yes we can. We are now transitioning to a paperless implementation of documents so it is possible.
      But it depends on how you can implement the control of documents.

      You need to consider the following control in addition to the requirements of “Document control procedure” you already have:
      1. The database where you save the soft copy is secured.
      2. There is a system of approval and monitoring that is implemented before you use the document.
      3. Only a read copy is shared, cannot be edited by an unauthorized person.
      4. A database back-up and maintenance is regularly performed.

      I hope this helps,

  5. HENRY
    | Reply

    Dear Edwin
    How do you calculate uncertainty measurement for PRV calibration?

    • Hi Henry,
      Below are the uncertainty contributors that I can recommend to include in the calculation of PSV/PSV measurement uncertainty.
      It is the combination of TYPE A and TYPE B contributors.
      1. Repeatability
      2. Effect of temperature
      3. Set pressure tolerance
      4. Drift
      5. Resolution of standard
      6. Reference Standard Uncertainty
      7. Reference Standard Stability

      I hope this helps,

  6. Joe
    | Reply

    What regulatory requirement is 4 years??

    “This is also a requirement of regulatory bodies that we need to follow.”

    How Long Can We Retain Calibration Records?

    One way to control records is to keep them for a designated period. The recommended retention period for technical records in calibration or testing is at least 4 years. Be sure that it is documented under the control of records procedure.

    A longer storage period for calibration records is required because some records are needed during performance review or history of data to be used during quality control.

    This is also a requirement of regulatory bodies that we need to follow.

    • Hi Joe,
      The regulatory requirement is for the calibration records to be kept for at least 4 years.

      Thanks for reading.
      Best regards,

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