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Posted: Thu Jul 24, 2008 4:38 pm
by Antonio
This setup only uses one microphone so is easier to setup. Moving the mic in the middle or using the time correction (speed of sound>) it achievable with one mic. Why use two...?
Posted: Fri Jul 25, 2008 7:52 am
by Sticky_Tape
Does the slash in distance/time=speed?
Posted: Fri Jul 25, 2008 1:20 pm
by jimmy101
Sticky_Tape wrote:Does the slash in distance/time=speed?
Yes. Divide the distance in feet from the muzzle to the target by the time between the two peaks in the recording.
The distance can be pretty much whatever you want, you just need to know what it actually is to a reasonable degree of accuracy.
Posted: Fri Jul 25, 2008 2:18 pm
by Sticky_Tape
Thanks Jim it was confusing.
Posted: Fri Jul 25, 2008 3:17 pm
by Antonio
Sticky_Tape wrote:Thanks Jim it was confusing.
lol that was the only dividing sign I could find. but yeah its basic if you just put the mic in the middle.
Posted: Tue Dec 16, 2008 12:35 pm
by ross_brigoli
Check this out. No need to manually compute.
Here's my home made chrono.
http://briggs69.blogspot.com/2008/11/pc ... hrono.html
Posted: Tue Dec 16, 2008 12:51 pm
by starman
Nice work there Ross. Too bad parallel ports have all but disappeared on modern computers.
Posted: Tue Dec 16, 2008 12:54 pm
by brplatz
Actually i did this too, possibly before you.
Here
I used a mic input for the data which is still there on most computers nowadays.
I am sorry for bringing an old topic back to life....
Posted: Thu Jan 08, 2009 9:52 pm
by jammerjam
but I have a question for those who are in the know.
I recently purchased a new rifle, an AGM MP-001 sniper rifle, and wanted to see what the fps was on it. I have an
audio file that I took from this rifle using a piece of software called
SoftChrono. Now I took the shot from 20 feet away inside with the mic, mono, at the 10 foot mark. I had a metal plate at the target spot, yeah I know... I had a lot of ricochet!, and had a really good report sound when the bb hit the plate. SoftChrono reported both fire, and target hit but it returns the FPS as being 1221 fps.......
Sorry about this post... I figured out my problem... I had my trigger levels set wrong, AND had some setting wrong.
So.. I apologize for reviving this post, but there is a really nice software based Chrono that appears to be pretty accurate. Although I don't like the results I got.. 340 fps is really low....
JAson
Posted: Thu Jan 08, 2009 10:03 pm
by rp181
brplatz, Yours is quite different, ross uses a computer to automatically get the readings. This also helps in keeping results consistent. I was recently looking for a way to interface a serial cable to a computer, but i deal with java.