The purpose of this PAK Tip is to present the "Free formula parameters" functionality
of the Arithmetic module which allows you to vary parameters in a predefined way.
When calculating in the Arithmetic module, some functions require input parameters in the formulas used.
In the following example, we start from the time recorded in the measurement to perform various calculations. The data contains the signal from an accelerometer and two rotational speeds:
We first calculate the 3D Autospectrum of the accelerometer's “Throughput”, with a number of blocks of 8192, a Hanning window, no averaging, an Overlap of 25%, all depending on the engine speed channel.
Then we want to filter this APS_3D in Band Pass, between 2 frequency terminals.
Note: the “BP_RM” function performs a Band Pass Removal, the datasets outside the considered frequency range are removed.
Finally, we calculate the overall level of this APS_3D filtered Band Pass.