PROCEDURE
1) remove the lower belt guard
2) position the mobile phone so that the microphone is very close to the strap, in the center of the lower span
3) press the START button
4) in 10 seconds, pinch the belt in the middle of the lower span several times (3-4 times)
5) at the end, the measured voltage is reported in newtons ([N])
6) if necessary, reposition the mobile phone, press the RETRY button and repeat from step 4

For more detailed information see the "Video tutorial".

Make sure to carry out each operation in compliance with the safety regulations and using all the necessary accident prevention devices.

ATTENTION
The app is a comfortable, simple and practical tool, but it is not an official measuring tool.
Use "Sonic Tension Meter" to get certified values.