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Altitude vs. Barometric pressure

 
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  #22  
Old 08-07-2005, 10:59 AM
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Re: Altitude vs. Barometric pressure

You are correct in your statments.

This program at this time doesnt utilize humidity. It will in the future. It does however utilize pressure, altitude and temprature. Users may choose between actual pressure at location, which eliminates the need for an altitude input. If users select altitude, then they can enter their local pressure based on wheather reports. The pressure they find on these reports will be corrected from actual to sea level. Either way they choose, they will be getting very accurate ballistics. In the future they will get even better figures when humidity is added. Fortunatly, the differance between 0% and 100% is a mere few inches at 1000 yards with medium calibers.
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  #23  
Old 10-18-2005, 09:15 AM
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Altitude vs. Barometric pressure

I appreciate all the input shared in this post.
Now let me make sure I have this straight.
When taking readings (Barometric Pressure) from my Kestral into Exbal and I put the actual reading (BP) from the Kestral in, I leave the altitude on exbal at sea level or zero even though I am actaully at 8,500 ft. Correct?

Next question, is that the only thing I would do different as far as putting in information?

Thanks! I just want to get this straight in my head.
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  #24  
Old 10-18-2005, 10:34 AM
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Re: Altitude vs. Barometric pressure

XP, yes. And yes. [img]/ubbthreads/images/graemlins/smile.gif[/img]
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  #25  
Old 10-18-2005, 10:45 AM
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Re: Altitude vs. Barometric pressure

Thanks for the response Charles.
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  #26  
Old 10-19-2005, 01:23 AM
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Re: Altitude vs. Barometric pressure

Gentlemen,
If I'm wrong I want to be corrected, but it's my understanding that Exbal... let me quote what Perry says about it:
[ QUOTE ]
Altitude (feet)
Used to determine speed of sound. Also may be used to calculate standard atmospheric pressure.


[/ QUOTE ]
Sorry... I did not mean to post it...read my next post.
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Jesus Christ the same yesterday, and to day, and for ever.

Our Lord Jesus said that as it was in the days of Noah and
also as it was in the days of Lot so it shall be in the days...
It's happening again!!! God sent to us His prophet, and His Word
to this generation and we once more are rejecting it as was prophesied!!!

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  #27  
Old 10-19-2005, 01:48 AM
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Join Date: Feb 2005
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Re: Altitude vs. Barometric pressure

Perry also says this:

[ QUOTE ]
A distinctive feature offered by Exbal is the ability to capture and remember sight in conditions. Lets suppose that you establish a great load for your brand new 300 Win Short Magnum with a 180 gr bullet chronographed at 3070 feet per second. Lets say you live in Corpus Christi, Texas which is 50 feet above sea level. Further lets assume you that you sight in your rifle during June when the temperature in early morning (when the wind is minimal) will be about 80 degrees Farenheit. Not only that, but you have established a sight in such that your bullet path is never above three inches high, or below three inches low all the way out to 275 yards. This concept is called point blank range. In this case you could aim at the middle of a six inch target and always strike it if it is within 275 yards.

Preparation: Lets assume you have put a lot of effort into establishing this load and practicing, and have used up two hundred rounds of ammo (and precious barrel life). Now you get the good news that you drew an Elk permit in Wyoming. You will be hunting at 10000 feet elevation and the temperature is typically 30 degrees in late October. Without a ballistic calculator you will have no choice but to try and sight in again when you get to Wyoming. This may not work out too well because you will probably not have a bench rest to shoot from and you will surely make a lot of noise doing it. Trying to sight in across the hood of a pickup truck leaves a lot to be desired.

Exbal offers an alternative to that scenario. If you have Exbal “remember the sight in conditions” you can establish field conditions (altitude, temperature, etc) that match the ones you anticipate in Wyoming. Then Exbal will determine the bullet path that will occur in Wyoming, even though you sighed in at sea level. You can use the Excel interface to create a reference card and print it out and laminate it to carry with you. Now you can take full advantage of all the effort you put into creating your ideal load and you will know exactly how it will perform on your hunting trip. Having one less thing to worry about is a good thing. Thus another reason for using Exbal is that it enables you to get ready in advance.

[/ QUOTE ]

Therefore it's important that when using Exbal you input the elevation you zero-in for including barometric pressure, temp. and humidity... you save this info. and when you move to different elevations you input your new information including elevation and Exbal will give you the right info. If you make the Elevation zero then you're defeating the purpose.
Remember, for barometric pressure you want to enter is not the corrected pressure... the absolute pressure. If you do not have that info. then check the box next to it and Exbal will calculate the Standard Pressure for that given Elevation... that's another reason you need to input the elevation you're shooting at.

I really know how to use the Explorer Ballistic Program, and to 1000 yards it gives exactly the same values with Exbal. I played with both programs and using different elevations and they both agree. In Ballistic Explorer you enter the sea level corrected Barometric pressure for what ever elevation you're shooting at, you also enter the Elevation you're shooting at and when you change Elevations the barometric pressure is changed for you automatically; this takes place inside the program to my understanding.
I hope all this helps... We just have to learn how each individual program works, how the programmer intended it to work.

Javier O Moncada.
__________________
-----------------------------

-----------------------------
HEBREWS 13:8
Jesus Christ the same yesterday, and to day, and for ever.

Our Lord Jesus said that as it was in the days of Noah and
also as it was in the days of Lot so it shall be in the days...
It's happening again!!! God sent to us His prophet, and His Word
to this generation and we once more are rejecting it as was prophesied!!!

---> As promised, God Sent His Prophet to us!
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  #28  
Old 10-19-2005, 08:03 AM
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Join Date: Dec 2004
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Re: Altitude vs. Barometric pressure

Now I'm a bit confused [img]/ubbthreads/images/graemlins/confused.gif[/img].....

I just purchased a Kestrel, which gives me the station pressure. Our altitude here is around 1200 ft. I've noticed that the readings I get are a little less than what the weatherman shows. Is this station pressure vs. corrected pressure? If so, wouldn't me putting in the altitude and my pressure readings result in bad data?
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