Final Report 2006-09-30
The comparison has been completed and the results are available in the KCDB.
Progress Report 2006-03-31
From 2000 to 2002 (circulation period Jan. 2000 to June 2001), the BIPM Key Comparison CCAUV.V-K1 (Vibration) was performed with 12 national metrology institutes (NMIs) from different regional metrology organizations (RMOs) worldwide as participants (with PTB as Pilot Laboratory). The 5 RMOs APMP, COOMET, EUROMET, SADCMET and SIM participated in the key comparison CCAUV.V-K1.
It is required (cf. Mutual Recognition Arrangement MRA) that the key comparison reference values to be achieved as the main result of the key comparison be disseminated in regional comparisons to follow. For this purpose, the EUROMET comparison in accelerometer calibrations is required.
In accordance with the key comparison CCAUV.V-K1, the task is to compare measurements of sinusoidal linear accelerations and accelerometer calibrations in the frequency range 40 Hz to 5 kHz. To calibrate two accelerometers, Primary vibration calibration by laser interferometry in accordance with ISO 16063-11:1999 or Secondary vibration calibration by the comparison method in accordance with ISO 16063-21 shall be used. The latter method shall only be applied if the participating laboratory is supplied with traceability by primary calibration of reference accelerometers at the PTB on the basis of the agreed EUROMET project ref. No. 198. As transfer standards, two types of piezoelectric accelerometers are to be used: standard accelerometer (single-ended), type 8305 WH 2335, and standard accelerometer (back-to-back), type 8305 (manufacturer Brüel & Kjær). The latter accelerometer will be provided by the PTB pilot laboratory in two versions: For primary vibration calibration, the participating laboratory will obtain an accelerometer type 8305 with the top surface polished (reflectivity 80% or higher) for sensing the motion without any additional reflector, and for comparison, the participating laboratory will obtain a usual version allowing the single-ended standard accelerometer of the respective laboratory to be mounted on the top surface. The measurand is the magnitude of the complex charge sensitivity. The calibrations shall be performed at the frequencies of 40 Hz, 80 Hz, 160 Hz, 800 Hz, 2 kHz and 5 kHz. The preferred acceleration amplitude is 100 m/s² (a range between 10 m/s² and 200 m/s² should be complied with - maximum 300 m/s²). After a preparatory stage carried out at the PTB from July 2002 to June 2003, the circulation period started in July 2003 and was finished in March 2005. The final report will be submitted in 2006.