How accurate is your chronograph?
- Thread starter Airgun-Revisions
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On what " calibrated" precise chronograph are they going to arrest you with ? I do got to guess and assume that these manufacturers pull one in ten thousand units off the assembly line and check it with somthing somehow ... Then what that somthing being checked with?
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This video provides a detailed discussion of the UK 12fpe limit. No twists and turns to try and obscure the topics importance. The presenter said the UK uses calibrated scan AR chronos. If you won't accepted those without a Tolkenish family tree going back to the most accurate chrono in all of history, that's your problem.
(Nor should anyone consider it a valid argument)
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There isn't a definitive way to pinpoint chrono accuracy at home, that's for sure.
What is close enough for me are
1) I compare to another chrony or two and if it's consistent, I'm good.
2) I know within a WAG what velocity my tune will provide, so I can get in the ballpark.
3) I can then shoot different distances using the velocity plugged into a ballistics calculator and see if it jives.
What is close enough for me are
1) I compare to another chrony or two and if it's consistent, I'm good.
2) I know within a WAG what velocity my tune will provide, so I can get in the ballpark.
3) I can then shoot different distances using the velocity plugged into a ballistics calculator and see if it jives.
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Perfect timing this pops up again!
Got my yearly measurements/calibration done - with new designs, new circuits, and new software.
Absolutely bonkers accuracy & really happy with the results!
Physical dimensions of the sampled units were within 0.01mm (uncertainty of 0.003)... I still dont get why people dont like 3D printing
Now for the data....
3 Units each received 300 sample shots (electronically triggered) all at 1,000fps
These are different dimensions to the regular NateChronys - so expect the shot-shot resolution of a NateChrony to be around 0.25fps @ 1,000fps & within the usual 1fps @1,000fps of actual speed.
That's how I know my Chronographs are accurate, I put about 3 days of work in to make sure.
Got my yearly measurements/calibration done - with new designs, new circuits, and new software.
Absolutely bonkers accuracy & really happy with the results!
Physical dimensions of the sampled units were within 0.01mm (uncertainty of 0.003)... I still dont get why people dont like 3D printing
Now for the data....
3 Units each received 300 sample shots (electronically triggered) all at 1,000fps
- Unit1:
- Spread: 0.11fps
- Difference from actual ~1,000fps measurement: -0.00087fps (avg)
- Unit2:
- Spread: 0.09fps
- Difference from actual ~1,000fps measurement: 0.00127fps (avg)
- Unit3:
- Spread: 0.11fps
- Difference from actual ~1,000fps measurement: -0.00099fps (avg)
These are different dimensions to the regular NateChronys - so expect the shot-shot resolution of a NateChrony to be around 0.25fps @ 1,000fps & within the usual 1fps @1,000fps of actual speed.
That's how I know my Chronographs are accurate, I put about 3 days of work in to make sure.
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Geeez Louise that’s serious work!Perfect timing this pops up again!
Got my yearly measurements/calibration done - with new designs, new circuits, and new software.
Absolutely bonkers accuracy & really happy with the results!
Physical dimensions of the sampled units were within 0.01mm (uncertainty of 0.003)... I still dont get why people dont like 3D printing
Now for the data....
3 Units each received 300 sample shots (electronically triggered) all at 1,000fps
Mounting the units back to back - we saw a difference of 0.34fps between the units, so we'll average that down to ~0.1fps & re-test.
- Unit1:
- Spread: 0.11fps
- Difference from actual ~1,000fps measurement: -0.00087fps (avg)
- Unit2:
- Spread: 0.09fps
- Difference from actual ~1,000fps measurement: 0.00127fps (avg)
- Unit3:
- Spread: 0.11fps
- Difference from actual ~1,000fps measurement: -0.00099fps (avg)
These are different dimensions to the regular NateChronys - so expect the shot-shot resolution of a NateChrony to be around 0.25fps @ 1,000fps & within the usual 1fps @1,000fps of actual speed.
That's how I know my Chronographs are accurate, I put about 3 days of work in to make sure.
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Nice dataPerfect timing this pops up again!
Got my yearly measurements/calibration done - with new designs, new circuits, and new software.
Absolutely bonkers accuracy & really happy with the results!
Physical dimensions of the sampled units were within 0.01mm (uncertainty of 0.003)... I still dont get why people dont like 3D printing
Now for the data....
3 Units each received 300 sample shots (electronically triggered) all at 1,000fps
Mounting the units back to back - we saw a difference of 0.34fps between the units, so we'll average that down to ~0.1fps & re-test.
- Unit1:
- Spread: 0.11fps
- Difference from actual ~1,000fps measurement: -0.00087fps (avg)
- Unit2:
- Spread: 0.09fps
- Difference from actual ~1,000fps measurement: 0.00127fps (avg)
- Unit3:
- Spread: 0.11fps
- Difference from actual ~1,000fps measurement: -0.00099fps (avg)
These are different dimensions to the regular NateChronys - so expect the shot-shot resolution of a NateChrony to be around 0.25fps @ 1,000fps & within the usual 1fps @1,000fps of actual speed.
That's how I know my Chronographs are accurate, I put about 3 days of work in to make sure.
Do you have temperature compensation? I'm sure the distance between sensors contracts as the housing gets cold.
Also what do they do to create 1000.00 fps projectile? (Is it attached to a rotating wheel or something?)
David
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Interesting this topic resurfaces. A couple days ago I repaired some leaks on my gun. Got it all back together and the settings close. Started shooting with my FX chronograph while watching groups and making slight adjustments. The velocities jumped around quite a bit. To the point that I cleaned the barrel and looked for a loose probe or something. Still had a substantial ES per magazine. Today I decided to shoot from my outdoor bench and I use a Lab Radar when I do. Over the course of two magazines I had a ES of 6. Hmmm.
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No compensation for thermal expansion - you're looking at around 0.03fps per degree at worst, insignificant in relation to everything else going on.
And there's a few things I put in place to assist. Hot climates - choose the stone/granite colour
There's no way to create a projectile at a certain known speed - i've spoken with NIST, and a few universities & ballistic places - nothing exists that I can find.
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Interesting.No compensation for thermal expansion - you're looking at around 0.03fps per degree at worst, insignificant in relation to everything else going on.
And there's a few things I put in place to assist. Hot climates - choose the stone/granite colour
There's no way to create a projectile at a certain known speed - i've spoken with NIST, and a few universities & ballistic places - nothing exists that I can find.
I guess if the purest accuracy is required there’s always Invar. And repeatability is far more interesting than absolute accuracy.
Do you know then how they trip the chronograph to simulate 1000.0 fps?
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Repeatability - if you dont have a power limit & looking to tune/test/verify, 100% correct
Simulate 1000fps - I simulate the timing circuit electronically on mine at 250, 500, 1000, 1500fps electronically when I program to check all the timing circuits.
You basically just trigger the sensor outputs/timing circuit inputs as required by the specific circuit.
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Precision Rifle Gear - New Athlon Rangecraft Chronograph-Garmin Xero Killer?
That is the correct app. In the “hamburger” menu at top right, you can select “connect device,” and go through a couple steps (within the settings app to connect to the device via Bluetooth, and through the Athlon Ballistics app) to connect the device to your phone. Once connected, again in the...
www.snipershide.com Second to last post by Verminterror did some testing of doppler chronographs that you guys might find interesting. He used more than one of the same model units to test the accuracy claims and to see how closely they read to each other.
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Thought I had replied to this thread but I don't see it.
I use my Pro Chrono Digital for shot count and accuracy. I don't hunt per say, but I do pest when the opportunity presents it's self. As long as it is consistently accurate from shot to shot I don't really care how accurate it is compared to another unit.. within reason.
I don't tune for maximum power. I tune for a good bell on a non regulated gun with a low ES and a flat string and efficiency on a regulated gun.
I also want it to give me consistent readings from session to session so I can verify the health of my guns and diagnose issues if they arise.
The key to consistency with the Pro Chrono is to put every shot on the exact same path over the sensors. If I put the shot over the right side of the back sensor and the left side of the front sensor then I'm increasing the distance between the sensors and getting bad readings compared to right over the center of both. It ain't much but it adds up over a string.
I use my Pro Chrono Digital for shot count and accuracy. I don't hunt per say, but I do pest when the opportunity presents it's self. As long as it is consistently accurate from shot to shot I don't really care how accurate it is compared to another unit.. within reason.
I don't tune for maximum power. I tune for a good bell on a non regulated gun with a low ES and a flat string and efficiency on a regulated gun.
I also want it to give me consistent readings from session to session so I can verify the health of my guns and diagnose issues if they arise.
The key to consistency with the Pro Chrono is to put every shot on the exact same path over the sensors. If I put the shot over the right side of the back sensor and the left side of the front sensor then I'm increasing the distance between the sensors and getting bad readings compared to right over the center of both. It ain't much but it adds up over a string.
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