Accelerometry

Final Report 2024-04-30

The project should be closed as it has no longer any relevance for the partners.

The future of the project was discussed at the meeting of Sub-committee "Acceleration and Vibration" held in Dublin on 23rd April 2024 and it was decided to close the project. The decision was further approved by the TC-AUV meeting.

Progress Report 2009-04-16

Change list of participants and coordinator

Progress Report 2004-05-25

To transfer to the two UK NAMAS (UKAS) accredited laboratories, Endevco (recently changed to Bruel & Kjaer UK) and Sira, the technology which has enabled them to upgrade their facilites for accelerometry to an accuracy of 1 % using the comparison technique developed by PTB. This applies also to other partners (institutions) which joined the project later (Kistler, METAS, GUM, BEV, CEM). Beyond the above accredited laboratories (SIRA, Endevco/Bruel & Kjaer UK, Kistler) and NMIs (METAS, GUM, BEV, CEM), non-accredited calibration laboratories (e. g. MIRA, and Castle Group Ltd. GB) have been directly supplied with traceability by primary calibration of accelerometers at the PTB. The PTB provides primary vibration calibration of reference and transfer standards (accelerometers, acceleration measuring chains) with expanded uncertainty (k = 2, P = 95%) <= 0.2 % from 0.5 Hz to 1.0 kHz, <= 0.3 % from 1.25 kHz to 4 kHz and <= 0.4 % from 5 kHz to 10 kHz, using sinusoidal acceleration.

For special investigations (i.e. long-term stability or linearity tests of accelerometers), an expanded uncertainty of 0.1 % is available.

In addition to the magnitude of complex sensitivity of transducers, the phase shift can be measured by laser interferometry in accordance with ISO 16063-11: 1999, too (expanded uncertainty <= 0.5° from 0.5 Hz to 4 kHz, <= 1° from 5 kHz to 10 kHz).

Primary vibration calibrations are also available for velocity transducers and displacement transducers and measuring instruments (displacement amplitude range 1 nm to 0.5 m, frequency-dependent). In particular, the PTB provides primary calibration of laser vibrometers (preferably reference laser vibrometers) in the frequency range from 0.5 Hz to 20 kHz (expanded uncertainty from 0.2 % to 0.5 %, frequency-dependent).

Progress Report

To transfer to the two UK NAMAS (UKAS) accredited laboratories, Endevco and Sira, the technology which has enabled them to upgrade their facilites for accelerometry to an accuracy of 1% using the comparison technique developed by PTB. This applies also to other partners (institutions) which joined the project later (Kistler, METAS, GUM). Beyond the above accredited laboratories (SIRA, Endevco, Kistler) and NMIs (METAS, GUM), non-accredited calibration laboratories (e. g. MIRA, and Castle Group Ltd. GB) are directly supplied with traceability by primary calibration of accelerometers at the PTB.

PTB provides primary vibration calibation of reference and transfer standards (accelerometers, acceleration measuring chains) with expanded uncertainty (k = 2, P = 95%) <= 0,2% from 0,5 Hz to 1 kHz, <= 0,3% from 1 kHz to 4 kHz and <= 0,4% from 4 kHz to 10 kHz, using sinusoidal acceleration. For special investigations (i.e. long-term stability or linearity tests of accelerometers), an expanded uncertainty of 0,1% is available. In addition to the magnitude of complex sensitivity of transducers, the phase shift can be measured by laser interferometry in accordance with ISO 16063-11: 1999.

Absolute calibrations are also available for velocity transducers and displacement transducers and measuring instruments (displacement amplitude range 1 nm to 0,5 m, frequency-dependent).