Accelerometer calibration: a step-by-step guide

An accelerometer is a complicated electro-mechanical system, which usually contains a spring-mass system (piezoceramics and a seismic mass) and a build-in charge converter.
You need to check the device at least once a year to ensure, that the sensor performs according to its specifications and is still “healthy”.

RULA software allows you to perform sensor calibration using the in-built software module. It provides the following advantages: 

  • flexible settings and database functionality
  • automated procedure
  • generation of detailed reports 
  • calibration with Random signal, decreasing the time of procedure to >4 minutes

To perform calibration with the system connected, follow the steps below.

1. Choose the "Sensor calibration" option from the list of the test types on the Main tab.

2. Specify the reference sensor and shaker

Select the reference sensor and shaker on the Equipment tab.

Sensor calibration - Equipment tab

In this tab, you can specify up to three shakers. This is essential if the non-calibrated sensor has a wide frequency range, e.g. from 0.1 to 10,000 Hz. 

Select the shaker from a drop-down list in the left side of the tab. You can modify the shaker profile by clicking on the shaker icon.

Sensor calibration - Shaker drop-down list

Specify the reference sensor. To do so, press the Sensor Database button.

Accelerometer calibration - Reference sensor

A Reference Sensor Database window will open.

Accelerometer calibration - Reference Sensor Database

Specify the sensor under calibration and its parameters on the Sensor Parameters tab.

Accelerometer calibration — Sensor Parameters tab

The sensor parameters are stored in the database. Open it by pressing the Sensor Database button.

Accelerometer calibration — Sensor database

If the chosen sensor has already been calibrated, its parameters will appear in the database, you can simply choose it from the drop-down list.

Accelerometer calibration — choosing a sensor in the Sensor database

If such a model has not been calibrated earlier, you have to input necessary data in all empty fields.

After selecting the sensor, specify the serial number in the corresponding field:

Accelerometer calibration — entering a factory serial number

2. Specify measurement parameters

Accelerometer calibration — specifying measurement parameters

You can fine-tune the specifications in the Measurement Parameters tab. The default settings allow for precise calibration, and you only need to change a few fields:

  1. Environmental parameters – temperature, humidity, etc., which are going to be placed in the report;
  2. Measurement mode – Sine or Random. The Random mode is used for a wide spectrum of Random vibration, which allows for faster calibration. However, it's not advised to use Random signal on low frequencies due to high displacement and acceleration values which can damage the equipment. Sometimes using the Sine signal is required by a standard.

3. Run the calibration

After you’ve set the parameters, a test window appears.

Accelerometer calibration — running the calibration

A combined oscilloscope and spectrum scope window is displayed on the right side of the window. Signals from both sensors – reference and under check – are shown here.

There are two graph windows in the middle of the screen that display the calibration results — FRF and phase.

Press the Start button to begin calibration. The tooltip window appears:

Accelerometer calibration — a tooltip window

Press the Continue button in the tooltip window to start calibration.

All measurements and changes in frequency are done automatically. The software will form a report at the end of the calibration process.  

Accelerometer calibration — certificate of calibration

Congratulations, you've completed the calibration process!

If you have any questions regarding the accelerometer calibrationcontact our 24/7 technical support via email or call +371 6610 2166. Our experts can organize an online demonstration via Zoom or TeamViewer and showcase the module in more detail.