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:
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:
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.
See also:
- Shaker calibration system
- Test-run of the shaker system
- Evaluation of vibration acceleration and frequency non-uniformity
- Evaluation of vibration acceleration, vibration displacement, and frequency range
- Evaluation of acceleration and/ or displacement harmonics ratio
- Calculation of lateral components ratio
- Calculation of distribution non-uniformity ratio
- Calculation of trunnion resonance frequency and the first resonance frequency of the system
- Evaluation of the shaker table vibration noise level
- Evaluation of the tolerance limit for maintenance of the acceleration and/ or displacement level at the control point