Calibration

Calibration must be undertaken by a UKAS/ILAC accredited calibration laboratory, accredited for the specific class of calibration required.

Trace, manufacturers, or verified calibration is not acceptable.

The complete instrumentation assembly, such as an anemometer and any additional hoods must be calibrated together as a working measurement system. Each item must be separately identified on the calibration certificate.

All equipment shall be labelled to be both identified and traced back to the calibration certificate.

Calibrations to ‘velocity’ are not permitted.

Where the airflow measurement instrument utilises a correction factor (K Factor) for its hoods, the correction factor must be uploaded as part of the upload calibration section in the ATTMA Portal to enable appropriate calculation and corrections.

Calibration Frequency

All equipment used is required to be annually calibrated.

Calibration Specifications

All the following specifications are required of all equipment used, which must all be undertaken by a UKAS/ILAC accredited calibration laboratory, accredited for the specific class of calibration required.

The equipment must be calibrated over the range it is to be used, typically 4 to 60 l/s (14 m³/h to 216 m³/h). Measurements outside of this range are not compliant.