Ok, here goes: my attempt at giving you all the info you need to get accurate, consistent readings from your Android smartphone chrony. Keep in mind, the app from ChronyConnect only works on Android phones. Sorry 'bout that but we're not going to have an "Apple vs Android" debate in this thread and all comments along those lines will be deleted.
Let's get the test envrionment set up first. You need a target that will make some pretty good noise when hit. A good thick piece of cardboard will work fine, a metal lid or somethinhg would work as well. You also need something to shoot through. This app is meant for airguns and needs that first "muzzle report" to time the shot and generate FPS numbers. I have a stand set up with a piece of newsprint to shoot through. It doesn't slow the shot down and makes enough of a "crack" to register. I stand right behind the paper and shoot through it into the target. Target and stand are 16' (192") apart.
My phone is set on a tripod halfway between the newspaper and the target and as high up as I dare to set it. One of the measurements you'll need is "Device to pellet path", that's how close the ball will pass over the phone. It's about 6" in this case.
On with it, then! FIrst thing's first, go to the Google Play store and search for Chrony Connect. Get the free version first and then go back for the paid one (like $3) if it works for you.
When you first open the app it will look like this:
Tap the "Menu" button indicated by my thumb in the pic and you will get this menu:
This lets you set up all your distances and ammo weight (for power readings). Start with distance in the "Target Options" menu. Distances can be set in a variety of different units of measure, I'm using inches.
First up "Muzzle to target": 192"
Next is "Device to muzzle": 96"
Then, "Device to pellet path: 6"
After that you can go to the "Projectile Options" menu and input your ammo weight. This will give you stats for the energy in the shot in ft/lb. You can Google "steel bearing weight" for a chart, this pic has several sizes on it, as well. Weight can be in grains or grams, I'm using grams.
After your all set you take your shots (3 at a time for the free version), check and repeat
If you have any more questions or if I've left anything out please don't hesitate to ask!
Edited by M_J, 27 January 2013 - 10:50 AM.