Hi
Yes it would be difficult to see on my recorder due to I’ve got the gain set to 1, if I set the gain to 8 you would see it very clearly,
but most people run their instruments With the gain set to 1, Each day I go through all the recordings and Look for any events that have been taking place against the background noise, the background noise can be a big problem especially if there is any high winds, low pressure,
In this event I set the gain to 8, which enabled me to find it then I selected and putting through a filter which enables me to see a clear signal
If my memory serves me correctly magnitude is automatically calculated by computers, Then the event would be checks by someone in that department
he would then give it a more accurate magnitude, based on other station timings
I am sttill learning it a fascinating science
mick 