Shock acceleration measurement

Progress, 16 April 2009

update of list of participants, update of coordinator

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Progress 25 May 2004

PTB provides traceability in the area of shock acceleration measurements. Primary shock calibrations of reference standard accelerometers (back-to back design) and transfer standard accelerometers (single-ended design) in accordance with ISO 16063-13 are available in the shock acceleration peak value range from 50 m/s^2 to 100 000 m/s^2 and in the shock duration range from 0.08 ms to 6 ms.

Shock pulses with approximately Gaussian acceleration shape are excited in the range 50 m/s^2 to 5 000 m/s^2 using a shock machine with air-borne hammer and anvil. For a given shock duration, different shock acceleration peak value can be generated (e.g. 150 m/s^2 to 2 500 m/s^2 at 2 ms shock duration). For a given shock acceleration peak value, different shock durations can be applied (e.g. 3 ms and 0.4 ms at 1 000 m/s^2 shock acceleration peak value).

Shock pulses with approximately Gaussian velocity shape are excited in the range 1 000 m/s^2 to 100 000 m/s^2 using a shock machine with wave propagation in a Hopkinson bar. Over a wide range of peak acceleration values, e.g. 5 000 m/s^2 to 50 000 m/s^2, the shock duration can be kept nearly constant. The expanded uncertainty of measurement (k = 2, P = 95%) is <= 0.5 % of the measurand in the range 50 m/s^2 to 10 000 m/s^2, and <= 1 % in the range 12 500 m/s^2 to 100 000 m/s^2. The measurand can be the shock acceleration peak value or the shock sensitivity of accelerometers, defined as the ratio of the amplitude of the accelerometer output to the shock acceleration peak value.

For special investigations (e.g. linearity tests of accelerometers), higher accuracy (e.g. uncertainty of 0.3 %) is available under certain conditions. For amplitude linarity tests of accelerometers up to 100 000 m/s^2, the PTB provides primary shock calibrations with signal processing in the frequeny domain in accordance with ISO 16063-13, Annex C.


Proposal

PTB provides traceability in the area of shock acceleration measurements. Primary shock calibrations of reference standard accelerometers (back-to back design) and transfer standard accelerometers (single-ended design) are available in the shock amplitude range from 50 m/s^2 to 100000 m/s^2 and in the shock duration range from 0,3 ms to 6 ms. Shock pulses with approximately Gaussion acceleration shape are excited in the range 50 m/s^2 to 5000 m/s^2 using a shock machine with air-borne hammer and anvil. For a given shock duration, different shock acceleration amplitudes can be generated (e.g. 150 m/s^2 to 2500 m/s^2 at 2 ms shock duration); for a given shock acceleration amplitude, different shock durations can be applied (e.g. 2 ms to 5 ms at 1000 m/s^2 shock acceleration amplitude). Shock pulses with approximately Gaussian velocity shape are excited in the range 1000 m/s^2 to 100000 m/s^2 using a shock machine with wave propagation in a Hopkinson bar. Over a large range of amplitudes (peak acceleration values), e.g. 5000 m/s^2 to 50000 m/s^2, the shock duration can be kept nearly constant.

The expanded uncertainty of measurement (k = 2, P = 95%) is <= 0,5 % of the measurand in the range 50 m/s^2 to 100000 m/s^2 and <= 1% in the whole range. The measurand can be the shock acceleration amplitude or the shock sensitivity of accelerometers, defined as the quotient of the amplitude of the accelerometer output and the shock acceleration amplitude. For special investigations (e.g. linearity tests of accelerometers), higher accuracy (e.g. uncertainty of 0,3%) is available under certain conditions.

Subjects
Acoustics, Ultrasound and Vibration (AUV)
Coordinating Institute
PTB (Germany)