Additionally, paste this code immediately after the opening tag:

Nature theme natural
Free!
See whats happening!

  • App World

  • My stream

HI STRANGER
If you tell me who you are, I can help you to find your friends on Freapp!
Google Login

Chronograph

This chronograph measures the average speed of an arrow shot from a bow to a target using sound. Currently te...

$ 5.99

Store review

This chronograph measures the average speed of an arrow shot from a bow to a target using sound.

Currently tested on Galaxy Note II.

Wind speed and temperature are the most significant factors affecting the speed of sound.

Temperature accounts for altitude. Humidity and barometric pressure are negligible.

The speed of sound is needed to adjust for the time sound takes to travel from the target back to the microphone after the arrow hits the target.

Select nearest wind speed by moving right side view of windsock up or down
10 mph ( 5 m/s, 15 kph): Leaves and small twigs in constant motion
20 mph (10 m/s, 40 kph): Moderate branches move, small trees sway
30 mph (15 m/s, 50 kph): Large branches to whole trees in motion
Enter wind direction relative to shot by rotating the windsock in the top view on the right side

Select nearest temperature in degrees
Select distance to the target in yards (or meters)
Select delay time, the time it takes to put your cell phone in your pocket, draw your bow, and aim.
Select duration, the time it takes to release the arrow after hearing the single chirp signal
plus the time for the arrow to travel to the target and the time for sound to travel from the
target back to you. Use 4 seconds for long distance shots, otherwise use 2 seconds.

Set Max Vel, the maximum estimated arrow velocity in feet per second, if you are shooting > 350 fps or when shooting at 20 yards and the sound of your bow does not quickly damp out.

Press , put phone in shirt pocket, nock arrow, draw bow, aim, and wait for 3 chirps, 2 chirps, 1 chirp, then release arrow as soon as you are ready, within half a second or so.

The button will change to other status messages when active, and can be pressed again at any time to cancel.
A blue sound signal will appear with a mark showing when the bow shot and when the
arrow hit the target. The velocity of the arrow will be reported in the box.
Press to listen for the shot and the arrow. Shoot again if the sounds were missed.
If you entered the wrong temperature, wind speed, or distance before you shot, make the changes, then
Press to update the speed calculation.

Press tab button to hide user interface. Press again to show user interface.

Change units from US to SI (metric), if you prefer.

No velocity will appear after a shot if sounds were missed from the arrow release or the arrow hitting the target. Try to refrain from talking during the shot.
Make sure the microphone is sticking out of your shirt pocket.
Try not to aim at a shot-out part of your bag target, or pin up a milk carton, so the arrow makes a louder sound when hitting the target.

Program has been tested on a Galaxy Note 2 phone out to 100 yards in 20 mph winds on a bag target, with arrow speeds > 360 fps.

Program works with cross-bows, recurves, and compound bows.

Size

13.0 MB

Last update

Nov. 2, 2013

Read more