The side rails are used to hold the light diffusers in place. The
diffusers reduce the glare of the direct sunlight. In doing so, the
sensors are able to better see the bullet as it travels between the sensor and
the diffuser. The sensor detects a shift in the light intensity as the
bullet moves over it. When you think about it, it is pretty amazing how it
works given how fast some of those small caliber varmint bullets are traveling.
The CED M2 Chronograph is powered by a 9 volt alkaline battery. The
battery is not included so make certain you have one (or better yet) two
available. The extra battery goes in your range bag so you won't ruin a
day at the range due to a dead battery somewhere down the road. If you
don't want to stash it in your range bag, there is a spare battery compartment
in the main unit itself. Pulling that slide in tab divider that the bottom
of the battery rests against allows an extra battery to be stored in the main
unit. Pull the tab, slide in the spare, reinsert the tab divider, and
insert the main battery. Pretty handy!
The sensors are wired to 20' shielded cables that plug into the rear panel of
the main unit. There are two jacks for the start and stop sensors as
shown. The plugs look to be standard 1/8" stereo plugs. A USB port, which connects to your PC via the supplied USB cable,
allows you to download chronograph data. CED provides the "Chronograph
Data Collector" software on a CD for use with the M2. (more on that
The M2 comes with a nice large easy to ready LCD display. As with any LCD
display, don't freeze it (sub-freezing weather) or cook it in the hot sun
(sitting on an un-shaded bench in Arizona in July). Operating specs, per
the owner's manual, indicate a range of 32 to 122 degrees Fahrenheit.
A calculator style keyboard provides the user with a pushbutton interface. The keypad provides good tactile (no, not tactical!) feedback. I'm not going to go through all the keys and functions....the owner's manual does a great job of describing their function and when/how to use them.
More CED M2 Chronograph
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