I have heard about two alternative methods
1. sound based
1. shoot through 2 hanging paper targets, record the impact sound with a microphone in the middle between the two targets, with the program audacity you can measure the exact time bewteen impacts and with that and the distance between targets you can calculate arrow speed. But somehow the speed of sound changes with ambient air temp. afaik? I thin this has to be included in the calculation?
How exact is this method and what do have I to watch for in making the least measuring error?
2. shoot an arrow of known mass into a pendulum of known mass , measure dislocation of pendulum and calculate arrow speed from there.
Which method is preferrable and has anyone used one of these and can give me some tips?
Are there other low-tech methods avaliable?