# EI-Calc. Description

## FFT calculations

**EI-Calc** uses independent FFT calculation algorithms for each one of the processes to increment the speed of the graphical solution. It performs the FFT calculations with fine Pre-Post processing parameters.

The resultant spectrum can be zoomed, measured, filtered with just a few mouse movements and graphical controls. You can also set the harmonics markers, maximum markers, Bearing frequencies markers in your spectrum or even set some Alarm frequencies. Every spectrum or signal graphic can be exported as a BMP/JPG image in order to configurate your analysis report.

Before FFT calculations, **EI-Calc** implements a DC offset remove algorithm. This process normalizes the signal removing the mean value from the signal. The resultant signal has a 0 mean value. This process eliminates inexistent low frequencies from your signal before performing the FFT algorithm.

## Million points FFT

In **EI-Calc** you can set the records preferences to any length that you want to get the precision that you are looking for. For example to get a precision of +- 1 CPM you should take a 50 seconds sample. To get an acuracy of +- 0.1 CPM you must take a 5 minutes sample. In this final case you will get a 13 million points FFT.

Real time spectrum analysis has by default a 0.1 second refresh interval, which is adjustable to any value that you want. However it won´t affect the precision of the FFT once the record is stopped, because when the record timed is elapsed, the full registered signal is recovered and printed on the screen with full FFT resolution.

## Demodulation filtering, Signal filtering

**EI-Calc** has many tools for filtering your vibration signal such as band pass filter, high pass filter, band stop etc. EI-Calc may also calculate the envelope for any signal. With this system you will be able to apply any custom filter before demodulating.

## Acceleration, Velocity and Displacement measures

Acceleration, Velocity and Displacement can be easily obtained trough integration a derivation formulas. They can also be calculated each one or all together on Real Time.

## Spectrogram function

Spectrogram is a Time based FFT Graphic. This means the **EI-Calc** can calculate the FFT of each second of your recorded signal and place it in a graphic.

## Calibration

All sensors are precalibrated with a sensitivity of 330 mV/g, however your computer will have to be updated to the correct value when first installing. This is a very easy task to do using a single voltmeter, some videos about this are offered with the software package.

## e-Mail Support

Please don´t hesitate to write to us regarding any doubt that you may have. Our e-mail is info@ei-calc.com and we will be pleased to answer to your questions within the next 24 hours.