Calibration validity guidance
Calibration validity is stated on the product brochure. It is 3 years for most products. The suggested re-calibration due date may be printed on a label on the instrument.
The maximum recommended re-calibration period for test equipment is defined by ISO 17025.
Mention of a re-calibration period on an ISO 17025 compliant calibration certificate is specifically rejected.
For optical power meters the maximum requirements are: 5 years for semiconductor optical detectors, and 1 year for digital meters using an electronic analogue / digital converter, or more frequently if the customer’s usage conditions or acceptable risk is beyond typical expectations for the test equipment. Many users decide that they'd like a 1 year asset management period.
Most commercial optical power meters depend on the stability of switched gain linear amplifier gain stages and an A/D converter to maintain their accuracy, so their calibration cycle is limited to one year, resulting in lifetime maintenance expenses considerably greater than the purchase cost.
However, Kingfisher power meters use a unique design. The meters continually self-calibrate the entire electronic signal chain using references stable to 0.1%, so this error contribution is eliminated, eg the gain stability of the amplifiers and A/D chain is irrelevant. Our suggested re-calibration period is given as 3 years.
For customers genuinely interested in demonstrating traceable calibration, this results in real lifetime cost savings, since the expense and inconvenience of a number of calibration cycles can be avoided.
If your instrument needs calibration, please follow guidance here.