6 months? 12 months? 2 years

How long is a calibration for UV measuring devices valid?

UV measuring devices are subject to a slight, natural aging process that affects the sensor sensitivity and thus the calibration. Factors such as intense UV exposure or environmental effects, especially dirt and fingerprints, can accelerate this aging process. Deposits on the sensor surface, for example dust or chemical substances, can reduce the sensitivity of the sensor.

This reduces the measurement accuracy, making calibration necessary to compensate for deviations. Regular calibration and careful monitoring of the sensors are therefore crucial to ensure high measurement accuracy and long-term stability.
 

Calibration is a quality assurance measure. The obligation to plan and carry out regular calibrations for UV measuring instruments that are used and that directly or indirectly influence product quality can be derived from many regulatory sources.

How do I find the appropriate calibration interval?

An appropriate calibration cycle is also suitable for verifying previous measurement results.
But how do you find the right calibration interval without losing sight of economic factors?

Some standards contain terms such as ‘at fixed intervals’ or ‘regularly’:

For example, the EU GMP guidelines on good manufacturing practice state in Chapter 3.41: ‘... calibrated and checked at fixed intervals using suitable methods.’
 

• ISO 9001:2018 requires ‘calibrated and/or checked at specified intervals or before use’.
• The FDA specifies specific requirements for the calibration of measuring instruments, which are regulated in particular in 21 CFR Part 820 (Quality System Regulation - QSR) and the Good Manufacturing Practices.
• The IFS Food standard for food and food packaging recommends: ‘All measuring equipment must be checked, monitored, adjusted and calibrated at specified intervals in accordance with specified, recognised standards/methods and within the relevant limits of the process parameter values. The results must be documented.’
   

We recommend an annual recalibration of the UV measuring devices and UV sensors. This period begins when the UV sensor is used and irradiated for the first time.

If a UV radiometer is mainly used in the laboratory and indoors without significant climatic or mechanical stress, the calibration interval of a UV measuring device can be extended. However, this is at the expense of process reliability.
 

Validity of a calibration certificate?

The calibration certificate reflects the properties of the calibration object at the time of calibration. The user is always responsible for determining and adhering to recalibration periods. If damage or contamination is suspected, we strongly recommend an immediate inspection.

 

Storage of a calibrated UV measuring device

If UV measuring devices and UV sensors are stored in a dry and clean place, the service life is not reduced and there is practically no ageing. Therefore, we distinguish between storage and use. Our internal records show no deviation in storage. So you can safely store the UV measuring devices and UV sensors as described in the data sheet.