Chrony Conundrum

[CDN_Stalker]

Originally Posted by mcguyver

Stalker, you're measuring most other guns at 2 times or more the velocity of the springer. Chronos can be notoriously unreliable as velocitites increase, and a 5% variance at 200 fps may translate into 10-15% variance at 500 fps.

If you try a battery-powered light source, and you still get wild drifting, ignore the voltage element as you will have bypassed that.

The LEDs I bought are battery powered and self contained units, and seem to be working well so far.

And if chronies are that unreliable as the velocities increase, then they wouldn't be used for firearm ammunition testing, as the variations would be in the hundreds of fps from shot to shot. Yes, I'm shooting double what the srpinger is, but it's still very slow compared to firearms.

[m102404]

So the LEDs work well, providing light directly (i.e. no diffuser between the light and the sensor) to the chrony? How high are they above the sensor (guessing about 12-14"?).

Thanks!

[CDN_Stalker]

I've just got the first stage diffusers on, and have the LEDs underneath it, so I'd say maybe 7-8" above the sensor. Works well enough that having the lights off and using only the LEDs I was getting good results (even was able to see the screen with the ambient light from the LEDs). So ya, works well, diffusers are only there to hold the lamps up.

[GraveTech]

Originally Posted by CDN_Stalker

Is funny, for all the info I've passed, have had quite a few interesting posts made regarding different light sources, yet no one has taken into consideration the different readings each night from two AEGs and one bolt action spring rifle, but are consistant night to night with the TM springer. If light was the main variable, the TM springer would yeild different readings as well, yet it constantly remains within roughly 10fps between 210-220fps with 0.20g.

Here's a hypothesis for you; since your previous tests have been done with none-battery powered light sources (and has been stated a few times before, these light sources flicker) the springer may have been shooting slow enough to pass the diffusers while the light is not flickering. If you are shooting the AEG and GBB, they may be fast enough to pass the diffuser on the lower-light cycle of the flicker. This depends on how wide the diffusers are.

Did I make any sense at all?

[Affliction]

I've read about people having issues with the F1 for AIRSOFT.

FYI

[CDN_Stalker]

Actually does make some sense Gravetech.

Thanks Fury.