# Calculating Velocity in the Toolbox

Stephen Hanly
Member, Administrator, Moderator Posts:

**62**adminThis example uses the train data (https://community.endaq.com/discussion/75/vibration-from-bridge-as-train-passes-overhead#latest) to calculate velocity in three ways:

- Straight integration and double integration
- Calculating a PSD, then integrating that
- Calculating a shock response spectrum pseudo velocity which tries to define severity (admittedly this is better for shock, not vibration data)

Here is the video of the analysis:

https://info.endaq.com/hubfs/velocity-integration.mp4

## Double Integration

First is the x axis

Then the y axis

Now the z axis

## PSD

The RMS of each is calculated:

- X Axis: 0.4g
- Y Axis: 1.0g
- Z Axis: 0.7g

Now calculating the PSD in velocity, here is the RMS:

- X Axis: 0.15 in/s
- Y Axis: 0.70 in/s
- Z Axis: 0.38 in/s

## Pseudo Velocity Shock Response Spectrum

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