I need help calibrating FX Pocket Chronograph

[Impact701]

I just bought a FX Pocket chronograph.

It consistently reads 15+ fps faster than my Pro Chronograph which seems to read the correct velocity, confirmed by Stelok.

I have tried to calibrate it to read the same as my Pro Chronograph but there seems to be a glitch with the app.
According to the owners manual you should be able to change the velocity + or - 2%
I'm able to add velocity but I cannot lower the velocity.

Thanks in advance

 

[SilentSquirrel]

following with high interest

 

[Impact701]

It is a problem with the app

 

[Hateful McNasty]

Seems to read correct... I guess you can say that with any one inless its super obviously off

Then do you really know if that pro crono is just not 15 fps slow , fast or anything spot on ? How'd you calibrate it? You just took that at face value in hope its close to any correctness, right?

 

[Impact701]

I have enter the velocity from my Pro Chronograph into the Stelok app. So when I shoot to 125 yards the app shows 35 clicks I hit spot on. If my M3 was shooting 15+ fps faster Stelok shows only 33 clicks I would hit low.
That's how I know my Pro Chronograph is closer to the correct velocity.

 

[Hateful McNasty]

Now of the fx is barrel mounted and the pro is sitting x amount away from the muzzle that would be fx faster like here you can see how much loss from muzzle to just 10 yards so that could be a factor in fps different readings?

 

[Impact701]

I was able to calibrate my FX pocket chronograph to my Competition Electronics Pro Chronograph by setting the calibration to -1.5

I'm shooting H&N Heavy.25 caliber 40gr.
10 shots
Pro Chrono H 987 fps
L 980 fps
AV 984 fps
FX Chrono H 985 fps
L 980 fps
AV 983 fps

 

[Trucker3573]

Projectiles slow quickly when they leave the barrel. Inches of differing distance away from the barrel that each chrono is can make a 15 fps difference. Just knowing how each type of chrono is set up differently in relation to the gun I bet this is the problem.

 

[bigHUN]

Over fifteen years of archery (FT and FITA) competition I learned that no two chronographs shows the same. In my club - several times along the years - we collected many brands and models for side by side comparison, this how I know. Friendly advise, pick one and stick with it.
With FX radar pretty much you need to place it where is no echo from surrounding objects, behind a muzzle alligned with the path. On my Impact I mount it below and on my L2 on the side of the barrel.

 

[IRBent]

My FX Pocket Chrony reads about 1% faster than my 90s model ProChrono, when the FX WILL WORK. Sent it in for service since it didn't work all weekend and missed maybe 80% of the shots Monday.

 

[Impact701]

My FX Pocket Chrony reads about 1% faster than my 90s model ProChrono, when the FX WILL WORK. Sent it in for service since it didn't work all weekend and missed maybe 80% of the shots Monday.

Try using this mount for your FX chronograph.
I have shot hundreds of shots and reads them all.

FX Chronograph Picatinny adapter - Midwest Elite Airgun

No longer do you need rubber bands or long poles holding your chronograph. With the Midwest Elite Picatinny adapter you can slide your chronograph right on to your picatinny rail.

midwesteliteairgun.com

I have the angled one for side mounting