Calibration and Calibration Certificates

When should you calibrate your equipment?

While there is no standard for how often you need your equipment calibrated, most people use their best judgment. Do you have an important project coming up where your measurements must be accurate? Then my suggestion would be to calibrate it before you start. Otherwise, Annually or Bi-annually works for most people. If you only use your multimeter to check standard voltages for example, “I need this output to be 24V. Yep, its 24V.”, then you can calibrate your equipment less often.

What does a calibration certificate look like?

The UL has a great reference for this, please see below for corresponding explanations.

Photo taken from Page 6 of Hard copies are uncontrolled and may not be up-to-date. Please see the electronic copy for the most up-to-date version.

According to the Underwriter Laboratories for a calibration certificate to be ISO/IEC 17025, it must have:

  1. A valid accreditation body endorsement for the calibrations performed (refer to example list of accreditation endorsements below) in the form of an accreditation body logo.
  2. A title (e.g. “Calibration Certificate”);
  3. the name and address of the laboratory, and the location where the calibrations were carried out.
  4. Unique identification of the calibration certificate (such as the serial number).
  5. the name and address of the customer
  6. identification of the method used
  7. a description of the condition of and unambiguous identification of the item(s) tested or calibrated
  8. the date of receipt of the calibration item(s) if this is critical to the validity and application of the results and the date(s) of performance of the calibration
  9. reference to the sampling plan and procedures used by the laboratory
  10. the calibration results with the units of measurement
  11. the name(s), functions(s) and signature(s) or equivalent identification of person(s) authorizing the calibration certificate
  12. where relevant, a statement to the effect that the results relate only to the items calibrated
  13. . the conditions (e.g. environmental) under which the calibrations were made that have an influence on the measurement results
  14. the uncertainty of measurement and/or a statement of compliance with an identified metrological specification or clauses
  15. evidence that the measurements are traceable
    Other Calibration services can be found here:

Here are some links to the calibration services offered by our suppliers:
B&K Precision
Cal Test Electronics
FLUKE Electronics
FLUKE Networks
Global Specialties -
Teledyne Lecroy
TPI (Test Product International)