# calibrating a chronograph



## edthearcher (Nov 2, 2002)

*pro crony*

call them they might exchange it for free. I have delt with them in the past there customer service is great. I dont believe there is any adjustment on them


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## SonnyThomas (Sep 10, 2006)

My understanding through speaking with a couple makers of chronographs is that there is no way to calibrate them. Erratic readings is usually a indication of something not right. The 8 to 10 fps faster would fall under the difference between chronographs, a reason for the 3% error factor under rules of different archery organization.
You mentioned lighting and batteries, but also that giving error to chronographs is being near electrical appliances, transformers, high lines, radio and tv broadcasting towers and the such.


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## EnglishKev (Aug 8, 2009)

You could line up 20 different chronographs from 10 different makers, and half of them would have a variation.
It's called manufacturing tolerances.
Several of us have chrono's over here, we normally compare results, and decide on an average speed reading.
From that we allow + or - on the appropriate machine to get the average, ie machine 1 reading as is, machine 2 deduct 7 fps, machine 3 add 4 fps.

Works Ok for us.

Kev


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## BowButla (Aug 5, 2009)

Thanks for the info..............


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## fletched (May 10, 2006)

You can get a can of air and clean the two clocks. The little openings will get dust down in them and can cause accuracy problems. I keep my chrono covered up when not in use to prevent it from getting dusty.


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## neo71665 (Jul 26, 2007)

EnglishKev said:


> You could line up 20 different chronographs from 10 different makers, and half of them would have a variation.
> It's called manufacturing tolerances.
> 
> 
> Kev


You can get 20 from the same maker and all 20 have a differences for that matter.


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## completepassthru (Feb 3, 2008)

There is no way to calibrate a Pro Chrono. I would take a cutip with alcohol and clean the sensor windows. If this and good batteries does not change anything that is about it. Do not place the unit near florescent lighting. If you want a chrono you can calibrate get a shooting chrony. They are the best imo.


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## SonnyThomas (Sep 10, 2006)

Shooting Chrony was one of the manufacturers that told me their chronograph couldn't be calibrated.

Florescent lighting can be overridden by regular lighting and a hood or strong sunlight. Florescent lighting by itself sure plays the dickens with them. Usually continually erratic numbers and letters just sitting under florescent lights.

There is a company that makes a chronograph using only electricity, no batteries. The way our shop goes through batteries I wish we had one. Someone always seems to forget to shut it off.


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## completepassthru (Feb 3, 2008)

SonnyThomas said:


> Shooting Chrony was one of the manufacturers that told me their chronograph couldn't be calibrated.
> 
> Florescent lighting can be overridden by regular lighting and a hood or strong sunlight. Florescent lighting by itself sure plays the dickens with them. Usually continually erratic numbers and letters just sitting under florescent lights.
> 
> There is a company that makes a chronograph using only electricity, no batteries. The way our shop goes through batteries I wish we had one. Someone always seems to forget to shut it off.


They will tell you that but trust me they can be and are calibrated.


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## TMan51 (Jan 25, 2004)

completepassthu said:


> They will tell you that but trust me they can be and are calibrated.


The way they work, you'd have to have an adjustment for the distance between the two sensor's/clocks, or the angle of the detectors. Unless that changes, the unit really can't go in/out of calibration.

Some chronographs may have those features, the low cost basement units, probably don't.


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## EnglishKev (Aug 8, 2009)

neo71665 said:


> You can get 20 from the same maker and all 20 have a differences for that matter.


Yep!

Kev


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