Accredited Calibration

Yokogawa A2LA Accredited Calibration ImageWhat is an Accredited Calibration Laboratory?

What does accredited calibration mean? Calibration is the comparison of an instrument's performance with a standard of known accuracy. However, all laboratory and even national standards have uncertainties of measurement, hence it is impossible to be 100% confident that an instrument is operating within its stated tolerance limits. Regular calibration by a laboratory, which can provide very low measurement uncertainties at the specific measurement points applicable to you, enables you and your customers to have confidence in your test results.

Yokogawa's  Newnan, GA Office

To support Yokogawa’s position as the world’s foremost supplier of Power Analyzers/Power Meters and Optical Test Equipment, Yokogawa Corporation of America’s Calibration Laboratory has maintained its accreditation by The American Association for Laboratory Accreditation, A2LA, and perform calibrations in accordance with ISO/IEC 17025:2005 and ANSI/NCSL Z540-1-1994. Certificate Number 3474.01.

The International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) first issued this standard in 1999. It is the single most important standard for calibration laboratories and is recognized around the world. Laboratories that are accredited to this international standard have demonstrated that they are technically competent and are able to produce precise and accurate test and/or calibration data.

Yokogawa’s ISO17025 accreditation is part of our commitment to our customers to provide excellent product support and calibration of their measuring instruments.

Customer benefits include:

  • Proper Calibration, Adjustment and Maintenance of the instrument to original factory specifications.
  • Confidence in the accuracy of the instrument calibration.
  • Traceability of measurements and calibrations to national standards
  • Calculation and documentation of the uncertainty values of the calibrated product.

To view the Accreditation Scope and Certificate, click here.

Click here to contact us in regards to this accreditation.


No measurement is ever correct. There is always an unknown, finite, non-zero difference between a measured value and the corresponding ‘true' value. In other words, a user can never be 100% sure that an instrument is operating within its specified tolerance limits.

However, there are steps that can be taken to minimize the possibility of a measurement falling outside specified tolerance or uncertainty bands.

Regular traceable calibration is a method for gaining quantifiable confidence in a measurement system by comparing the instrument's performance to a standard of known accuracy.

It is important to understand the difference between ‘calibration' and ‘adjustment'. Calibration is the comparison of a measuring instrument (an unknown) against an equal or better standard. A standard in a measurement is therefore the reference.

Instruments are adjusted initially at the factory to indicate a value that is as close as possible to the reference value. The uncertainties of the reference standard used in the adjustment process will also dictate the confidence that the indicated value is ‘correct'.

As the instrument ages, the indicated value may drift due to environmental factors (temperature, humidity, oxidation, loading etc.) which will also be dependent on the quality of its design and manufacture. To ensure that the instrument continues to operate within the manufacturer's tolerances, the instrument should be compared to the reference value on a regular basis (usually annually). If necessary, the instrument can then be re-adjusted.

The scope of our calibration can be downloaded here.

Yokogawa products which can be calibrated include:

  • Power analyzers and meters
  • Digital multi-meters
  • Oscilloscopes
  • DC and AC calibrators
  • Data recorders
  • Decade resistance boxes
  • Waveform analyzers
  • Data loggers
  • Function generators
  • Insulation testers
  • Signal analyzers
  • Current clamps
  • DC voltage standards
  • Source measure units
  • Optical power meters
  • Optical spectrum analyzers
  • Light sources

Precision Making