To analyze the AC output of the VR-6100 as an acceleration signal with FFT analyzer, the unit calibration will be done by the FFT analyzer. The methods to obtain the calibration value are follows.

 

1. Press the panel switch [Lv/Lva/Lvf] to select Lvf. The AC output becomes a signal which has passed through the filter when you select Lv or Lva.

2. Press the panel switch [△] or [▽] (LEVEL) to select suitable measurement range for the target object.

3. Press [CAL] switch to output the CAL signal.


Calculate the following formula to obtain the value of CAL signal in the unit of m/s².

The display value in the VR-6100 when CAL ON is A (dB)

In this case, the acceleration is B

 

FFT analyzer operation

Read out the voltage of overall value = C (Vrms) after processing the frequency analysis of CAL signal with the FFT analyzer.

 

 

Calibrate C/B (Vrms) as 1 m/s² by using the unit calibration function of the FFT analyzer from above functional formula of when the acceleration is B (m/s²), the voltage value is C (Vrms).

 

For the operation of the FFT Analyzer, please refer to the operation manual. By setting the search point to the value which is calculated by the previous formula, FFT Analyzer is possible to process the unit calibration without hand calculation.