How to convert the value of crash detect from imuX and Z

I checked the data of Imu X 6.33and general Z13.33 from the log When the moment the plane crash into the ground, how can I convert it to the value of crash detect thresh.

I have read it as For electric planes that don’t vibrate much during fight a value of 25 is good (that’s about 2.5G). For petrol/nitro planes you’ll want a higher value. Set to 0 to disable the collision detector.

But I don’t knwo how to do it? thank you for any help.