Chronograph?

Azrael256

New member
I keep reading about chronographs. I have a rough idea of what a chronograph does, but I don't know what it IS. Could someone describe one?
 

David Wile

New member
Hey Az,

A chronograph in its simplest form is a speedometer for bullets. What you can get today at fairly reasonable prices, however, is a lot more than just a speedometer. Basically, a chronograph is a computer than can measure the speed of a bullet as it passes through two screens which are usually located a short distance from the muzzle of the gun. The computer is connected to the two screens which sense when the bullet passes through. Based on the lapse of time for a bullet to pass through the two screens (the screens are set at a specific distance from each other), the computer calculates the velocity of the bullet at that point. Chronographs used to be an arm and a leg thirty years ago, but today you can get one for $100 to $200, and it will record and average strings of shots for you.

Best wishes,
Dave Wile
 

Azrael256

New member
Ok, thank you for the info, but I have one more question. When you say "screens", do you mean a physical screen, if so, what is it made from?
 

JA

New member
http://www.chrony.ca/english.mv

http://www.pact.com/chrono.html

http://www.oehler-research.com/

All of them work the same the screen is a photoelectic cell. Same thing as a solar battery charger. The photoelectic cell converts light into electicity. The shadow of the bullet going over the first cell causes a interuption in the electric out put of the cell which starts the timer. The shadow of the bullet interupts the electric out put of the second cell and stops the timer as it goes over it. The amount of time in miliseconds it took the the bullet to pass between the 2 cells is converted and displayed in feet per second or meters per second depending on which model/brand of chronograph you have.
 
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