In a vibration measurement of a rotating blade, I have the following information. The vibration signal is measured using an ICP accelerometer which has the following specification
- Measurement range: 50g
- Sensitivity: 100 mV/g
- max output voltage: ±5V
- Broadband resolution: 100e-6g
The variance of the acquired signal is
$$var_{aq} = var_{acl} + var_{adc} + var_{sig} \approx 6.2e-4 g$$
- $var_{acl}$ = variance of noise in the accelerometer
- $var_{adc}$ = variance of the ADC noise (quantization, jitter)
- $var_{sig}$ = variance of the vibration acceleration of the blade.
Assuming that $var_{acl} \approx \sqrt{\text{broadband noise of accelerometer}} = 1e-8 \text{g_rms}$.
From the specification sheet of the ADC, for the used input gain of 30db and sampling frequency = 51.2Hz, the $var_{adc} = 1e-12 \text{V_rms}$
Can anyone please help, how can I calculate the variance of vibration acceleration of the blade $var_{sig}$?