11/2/00 FFT (Optional) 11-13
To convert sensitivity to decibels use the following formula:
When the linear scale is set to zero
the 824 will read the input voltage.
Linear Scale (dB) =
20Log (1 volt / sensitivity)
For example:
The sensitivity of an accelerometer is 50mV/g. The Linear
Scale would be calculated using the following formula:
+26.0 dB =
20Log [1 volt / 0.05V]
Enter +26.0 dB into the menu item “Linear Scale” for the
correct scale level.
The accuracy of the linear units value is +/- 5 % of the true
value.
This table gives some examples of some typical Linear Scale
values:
Sensitivity
Linear Scale
(dB)
Units
100 mV/g 20 dB g
50 mV/g 26 dB g
25 mV/g 32 dB g
10 mV/g 40 dB g
5 mV/g 46 dB g
14.0 mV/Pa 37.08 dB Pa (2540)
44.5 mV/Pa 27.03 dB Pa (2541)
11.7 mV/Pa 38.64 dB Pa (2559)
47.5 mV/Pa 26.47dB Pa (2560)