Evaluation of the tolerance limits

The tolerance limits for reproduction of acceleration (displacement) level are evaluated in percentage form with 0,9 confidence coefficient in accordance with the formula:

Evaluation of the tolerance limits for reproduction of acceleration and displacement level at the control point - Formula 1

where: δr — AC voltmeter relative tolerance level;

δFR — FFT Spectrum analyzer FR unevenness limit;

δH — measurement additional tolerance limit (attributed to harmonics) – it is calculated in percentage form during measurements of parameter’s RMS value by the formula:

Evaluation of the tolerance limits for reproduction of acceleration and displacement level at the control point - Formula 2

KHC — the maximum value of harmonics coefficient at the control point in the analyzed frequency range in relation to 1;

δT — limit of additional measuring tolerance (attributed to lateral components) – it is calculated by the formula:

δT=KLCR×KLC

KLCR — maximum ratio of lateral components at the control point in the analyzed frequency range at the set load, %;

KLC — relative ratio of accelerometer lateral conversion, in relative units;

δt — additional measurement tolerance limit attributed to temperature fluctuations of the shaker table – it is calculated in percentage form by the formula:

δt=Kt×ΔT

Kt —  vibration transducer temperature sensitivity ratio, %/°C.