• Frank's Lesson's Contest

    We want to see your skills! Post a video between now and November 1st showing what you've learned from Frank's lessons and 3 people will be selected to win a free shirt. Good luck everyone!

    Create a channel Learn more
  • Having trouble using the site?

    Contact support

Kestrel's Barometric pressure, do you need to "true" it each day of use?

You don't want to use the DA if you've got a kestrel to work with. You want the actual station pressure.

You want to go into your Preferences and change from Simple to Advanced first of all.

Then when you get to your atmospheric conditions page...Check the box next to "pressure is absolute"
That will eliminate the "altitude" variable and make your "density altitude" variable change to "station pressure" which is what you want.

Then you can enter in your exact "station pressure" according to your kestrel. Assuming of course that you followed Franks advice and have your Kestrel set correctly.

Thank you.

Sent from my SM-N900V using Tapatalk
 
Sync question answer. It is up to you whether you want to sync your attitude and barometric pressure. If you know your attitude then baro will be correct when sync is on. The inverse is also correct if you know your baro then your attitude is correct with sync on. On my 4500nv neither of these settings affect density attitude it specifically says this in the instructions. If you want your attitude to relate to your density attitude then set your attitude to 0 ft. Your barometric pressure will then be wrong. This doesn't matter though because you need to choose how you are going to collect data. Either use density attitude or barometric pressure. Unless your super anal and want both but that will require two separate dope cards that will have the similar info. Density attitude is better because your dope cards can be instantly generated with modern shooting software. Your wind questions need refinement. The measurement your taking is at your location you might have 2 or 3 different winds to 1000 and they are constantly changing.

And thank you.

Sent from my SM-N900V using Tapatalk
 
Ok, thanks for the response. So because I am so dense. I don't need to sync to use da only. As long as altitude is set to 0 and pressure is set to 29.92.

2nd. When u look at wind if I capture the 3 o'clock wind insted of turning directly into the wind will the firing solution be the same?


Sent from my iPhone using Tapatalk
 
Da is completely independent of attitude and barometric pressure in regards to the 4500 kestrel. So it doesn't matter if you have sync on/off. The sync feature only affects the attitude and barometric pressure screens. So setting your reference attitude to 0 ft or barometric pressure to 29.92 inhg will give you what the kestrel is using to calculate DA. However these values are now incorrect and shouldn't matter to you because your going to use density attitude to create dope cards if this is what you are trying to do. I turn off sync because this is more of a weather feature than a shooting feature. I am only looking for DA and its difference throughout the day. Their are some really good threads about this.

Programming wind from your kestrel into your ballistics calculator. I wouldn't do it because it changes constantly and the extra time needed to input that info the opps wind just changed again. Remember your only getting a wind value at your location. Your not inputting the wind value at 400 yards which coming from the opposite direction. You miss the other wind value at 800 yards which is a head wind. My point is wind calling is the art of distance shooting. This is where taking a class pays off and shooting your rifle gives you the experience to make a good wind call. I hope this helps.
 
My kestrel 4000 has 2 places where I can change barometric pressure. The factory default under the section with:
OFF
memory options
measurements
graph scale
units
user screen
system
date time
language
restore
has baro set at 29.53 under the system choice.

When I go to user screen, I set baro reference under altitude to 29.92, and under baro, I set reference altitude to 0 (zero). However, this then gives me an altitude reading at my location of 360 feet, rather than the correct altitude of 236 feet.

So, with barometer altitude reference set to zero, and altitude reference set to 29.92, my altitude reading is wrong. Should I also change the baro reference under system to 29.92 also? I'll try it, and hope I don't mess up the factory settings..

OK, that didn't work. It now says I'm 10 feet below sea level, and I'm breathing air, even though I can see the ocean from here. I'll return the setting to the 29.53 in "system".
 
Last edited:
No,

Change the reference barometer to a value that makes your known altitude correct.

But you really don't need to mess with this, just use station (or absolute) pressure and temperature and forget about altitude.

Sent from my iPad using Tapatalk HD
 
Am I correct that the baro setting that shows up under "system" is irrelevant if I'm going to use station pressure?

Edited:
When I set the barometer screen to have the correct altitude of 236 feet, the barometer reading is 29.83. Then I went to the Altitude screen and in order to get the correct altitude of 236 feet, the reference barometer reading is 29.03. Obviously, something is wrong. Aren't these two things supposed to match?

Baro=29.83
ref= 236

Alt=236
ref=29.03

I'm still puzzled about the barometer setting that comes up under the "system" part of the setup. What is that barometer reading supposed to be? What impact does that setting have on the rest of the barometer and altitude readings?
 
Last edited:
Your altitude reading is wrong because a Kestrel is a Pressure Meter and not a GPS... it has not idea where you are in the world, only what the air pressure is, so it is basing your altitude off the air density. it will change every day.

The system barometric pressure is a calibration, so unless you have a way to calibrate it, I would leave it alone, and just hit the "restore" on the system and call it good.
 
I bought the system used, so I don't know if the calibration setting was the one from the factory.. I'll hit the restore button and see what happens to the setting. If it is still goofy, I'll call Kestrel on Thursday. I tried calling the other day, but the expert there was out until Thursday.

I actually read the instruction manual for the Kestrel, but it didn't answer my questions. I'm getting more useful information off this thread than from the manual. I don't use the Kestrel as a GPS, but I had hoped that the elevation I received was accurate. I got 3 different elevations for my location, and all were within a foot or two. But as I got the elevation information from various internet sources, I have no idea if it is accurate, or completely wrong. I really appreciate you (Lowlight) taking the time to help us out with this.
 
I used to calibrate my Kestrel off 737 altimeters, and just adjust the altitude in my Kestrel based off my cars GPS, now I do exactly as Lowlight says, out to 1 mile(farthest I have shot and made hits) LL method works, and works perfectly well for ballistics, for the love of God STOP arguing and just do it.
 
I appologize for coming across like I'm arguing as that is the furthest thing from my intent. I don't have either the propensity, nor the information to argue about things I don't understand..And getting this Kestrel to work in a useful fashion is one of the things I don't understand.

I came back on line to say that I did as lowlight suggested and hit restore on my Kestrel. It put the current barometric pressure into the system, and showed my altitude at -10. I have to look down from my house to see the ocean, so I know that can't be right. I have the altitude reference set at zero on the barometric pressure screen, and allowed the Kestrel to re-calibrate itself. After I hit the reset button, the pressure changed to ambient pressure.

I must have something set wrong as I know I'm not below sea level. I have gone through the manual, followed Lowlight's recommendations, but I'm still stumped.

My barometer screen reads 29.52, with zero feet as the reference.
My Altitude screen reads -10 with 29.52 as the reference.
Density altitude reads 1201.

In the calibration settings, after I hit reset, the barometer reading went from 29.92 to 29.52. Is there another screen I should be using, or somewhere I have neglected to input data?
 
I appologize for coming across like I'm arguing as that is the furthest thing from my intent. I don't have either the propensity, nor the information to argue about things I don't understand..And getting this Kestrel to work in a useful fashion is one of the things I don't understand.

I came back on line to say that I did as lowlight suggested and hit restore on my Kestrel. It put the current barometric pressure into the system, and showed my altitude at -10. I have to look down from my house to see the ocean, so I know that can't be right. I have the altitude reference set at zero on the barometric pressure screen, and allowed the Kestrel to re-calibrate itself. After I hit the reset button, the pressure changed to ambient pressure.

I must have something set wrong as I know I'm not below sea level. I have gone through the manual, followed Lowlight's recommendations, but I'm still stumped.

My barometer screen reads 29.52, with zero feet as the reference.
My Altitude screen reads -10 with 29.52 as the reference.
Density altitude reads 1201.

In the calibration settings, after I hit reset, the barometer reading went from 29.92 to 29.52. Is there another screen I should be using, or somewhere I have neglected to input data?

In the "barometer" screen, with the reference altitude set to zero, you are getting zero correction for altitude. The pressure shown with reference altitude set to zero is the station or absolute pressure (i.e. what it measures). Your station pressure is 29.52. That's what you want to use for your ballistic program (and turn off 'adjusted' or 'corrected'). If you're interested in long-range shooting only, you're good to go and can ignore all from here on :)

I'm a little bit confused by your post, but if you have 29.52 with zero altitude and -10 ft with 29.52 as reference pressure, I wouldn't sweat it. You're worried about 10 ft? Pressure changes very little in 10'. This is measuring extremely small values - it will never 100% agree and it will vary every few seconds by a small amount.

But why is it reading -10' at all rather than a few hundred above sea level? - it's because you don't have the correct value for the reference pressure. What you have told the unit is "if you see 29.52 as the pressure - you're at sea level". What you need to tell the unit is "if you see 29.52, you're several hundred feet above sea level". (PS - don't assume sea level is at exactly 0' either - altitude is a concept).

So, from the "altitude" screen, if you correct for the daily pressure by setting the reference pressure, the unit is ESTIMATING that your altitude is -10ft. e.g. if you tell the unit that sea level should be 29.52 and you are measuring 29.92, you are below it (more air above you). If you really need to know the altitude (and you don't for long-distance shooting), then you need to calibrate it on the day, since altitude is ESTIMATED from pressure and pressure changes with the weather (and location). So ONLY if you need to know/track altitude, you can use the 'altitude' screen and change the reference barometric pressure until the altitude reads the value that you know to be correct. Then when you gain/lose height, the pressure change will allow the unit to estimate your new altitude. Of course, you need to set this at least every day for maximum accuracy.
 
Farmer brown,
Thanks very much! I realize that the density altitude is the only really important measurement. My fear was that if I'm not getting elevation readings that are even close to what should be showing for my location (220-236 feet above sea level) that my density altitude readings would also be off. Perhaps 246 feet of error isn't worth messing with though. I'm new to using density altitude readings, so I am trying to figure out what is acceptable error, and what I need to correct.

Many thanks to all who are trying to help me with this. I'll call Kestrel today and speak with their "expert" to insure that the original settings, defaults, and measurements are GTG. I'll get the local airport's data before I call, so I will have that if it is needed. Hopefully, that will get my Kestrel "calibrated" properly, and then I can get readings at least within the acceptable margin of error.

If 500 feet of elevation is the acceptable margin, then my 246 feet of error (236 actual, plus 10 feet below sea level as read), then I am wasting time on insignificant differences.
 
I spoke with the "expert" at kestrel's customer service today and told him what I'm trying to do. Here is what I learned:

1. When I'm on the baro screen and set altitude reference to "0" on the baro screen, the altitude (on the altitude screen) is TOTALLY worthless and doesn't mean anything.
2. When I'm on the altitude screen and set the baro reference to the correct reading from the baro screen, it varies from showing that I'm either 5' above sea level, to 15 feet below sea level...but it isn't important.
3. If I'm trying to use the elevation screen and calibrate it to the baro screen, the standard acceptable variance on the elevation is +/- 25 feet. But this isn't important as I want to use Density altitude anyhow.
4. When I asked about the calibration screen, I was told don't worry about it, or mess with it. There is also a humidity calibration screen in the same area, and to calibrate that, I would need to buy a kit costing around $97.00. Because I'm going to use density altitude, it isn't important.

I have the Exbal ballistic program entered into a palm pilot for field use. I asked how to sync the exbal program with the Kestrel, using the density altitude...the expert couldn't help me there. For those who aren't familiar with Exbal, it asks me to either enter humidity, temperature, altitude, baro pressure, or there is a little box I can check that says "calculate std pressure". (This is under the field data screen.) Under sight in data, it asks for velocity, altitude, temp, pressure, humidity, and there are two boxes to choose "calculate std pressure", or "use field conditions".

When I try using the "calculate std pressure" box, I can enter zeros in everything but velocity and pressure. If I try to enter zero for pressure, the system shows a screen that says I must enter a value between 28-32.

So, I'm good with the density altitude and temperature on the Kestrel, but am wondering which is the best data to enter into the various screens on the Exbal program on order to get it to work with density altitude?

I'm genuinely thankful for the patience and help of Lowlight, Farmerbrown and others as I adjust to a different system. Any assistance coordinating the Exbal with density altitude will be much appreciated.
 
If you still have my ph# give me a call any time, & I'll answer all your questions. If you don't have my # post up when you'd like me to call you. I can help you understand, & get your ballistics set up correctly.
 
I spoke with the "expert" at kestrel's customer service today and told him what I'm trying to do. Here is what I learned:

1. When I'm on the baro screen and set altitude reference to "0" on the baro screen, the altitude (on the altitude screen) is TOTALLY worthless and doesn't mean anything.
2. When I'm on the altitude screen and set the baro reference to the correct reading from the baro screen, it varies from showing that I'm either 5' above sea level, to 15 feet below sea level...but it isn't important.
3. If I'm trying to use the elevation screen and calibrate it to the baro screen, the standard acceptable variance on the elevation is +/- 25 feet. But this isn't important as I want to use Density altitude anyhow.
4. When I asked about the calibration screen, I was told don't worry about it, or mess with it. There is also a humidity calibration screen in the same area, and to calibrate that, I would need to buy a kit costing around $97.00. Because I'm going to use density altitude, it isn't important.

I have the Exbal ballistic program entered into a palm pilot for field use. I asked how to sync the exbal program with the Kestrel, using the density altitude...the expert couldn't help me there. For those who aren't familiar with Exbal, it asks me to either enter humidity, temperature, altitude, baro pressure, or there is a little box I can check that says "calculate std pressure". (This is under the field data screen.) Under sight in data, it asks for velocity, altitude, temp, pressure, humidity, and there are two boxes to choose "calculate std pressure", or "use field conditions".

When I try using the "calculate std pressure" box, I can enter zeros in everything but velocity and pressure. If I try to enter zero for pressure, the system shows a screen that says I must enter a value between 28-32.

So, I'm good with the density altitude and temperature on the Kestrel, but am wondering which is the best data to enter into the various screens on the Exbal program on order to get it to work with density altitude?

I'm genuinely thankful for the patience and help of Lowlight, Farmerbrown and others as I adjust to a different system. Any assistance coordinating the Exbal with density altitude will be much appreciated.

BTW, density altitude is simply a single-number representation of air density.
Air density is always and only a function of temperature, pressure, and moisture content (that's it!)
A ballistic calculator needs air density and so it calculates it from what you give it.
A density altitude calculator can do the same thing - see Density Altitude Calculator - English/Metric, Relative Humidity
Really, ballistics needs air density in lb/ft^3 - I don't see any advantage in concocting another value such as density altitude.

It also looks to me like Exbal doesn't support it.

I don't know anything about Exbal, but there are some things in common with all ballistic calculators.
Many ballistics programs run their values at "standard pressure and temp" - which is a value that people accept as 'standard', most commonly from ICAO.
Typically you input pressure or temp or altitude and it 'guesses' the rest from the particular 'standard' model.
Ok for short distances, but in reality, I need to know the values for MY situation and it's never standard.
And with a Kestrel, you have all the exact values, so use them and no models are needed.

That's maybe the check box you see in Exbal.
The other check box "use field conditions" means to use the same info to compare the values from what you sighted in at.
With 100 yrd zero, it hardly makes any difference, but imagine you have a 300 yard zero at sea level and then go to 5000' and want to shoot at 1000 yards.
Your zeros aren't zeros ANY more - that's what that check box is for.

Good luck,
Cheers, Farmer
 
Last edited:
I'm still having trouble feeling certain I have my kestrel set correctly. I wish I had just left it set from the factory but 2 yrs ago when I bought it I thought I needed the altitude to be correct and have been messing with it ever since. I have the 2500, I understand what everybody has been saying but the 2500 doesn't have all the options the 4500 does so I cant go set reference altitude to 0 and baro to 29.92. I have alt and elevation only if I change one it effects the other. I live close to the sea level so today I went down to the shore and adjusted my reference baro until I got 0 alt. Is it correct now? Because my reference baro was like 29.71 or something for me to get my alt to zero. Thanks for the help
 
If the 2500 doesn't have a reset feature then go to an airport, & set the pressure to match the pressure meter there. The only things we as LR shooters are interested in is the station pressure, temp, & humidity.
 
If the 2500 doesn't have a reset feature then go to an airport, & set the pressure to match the pressure meter there. The only things we as LR shooters are interested in is the station pressure, temp, & humidity.

I like this plan. I drive by a local controlled airport on the way to my shooting spot. I wouldn't have thought of this and I trust that they have a very accurate baro to calibrate to. Big Thanks.
 
I like this plan. I drive by a local controlled airport on the way to my shooting spot. I wouldn't have thought of this and I trust that they have a very accurate baro to calibrate to. Big Thanks.

Hi - check out this site: National Weather Service : Observed Weather for past 3 Days : Bremerton Ntnl Awos and this: AirNav: KPWT - Bremerton National Airport

You'll see Bremerton National (I presume near you) was 30.38 at midnight on 3-4 Jan but 29.92 a few days ago - you'll see it vary more than this with weather fronts, etc.
It's 444 ft high.

Next time you drive past, just make sure your Kestrel is in the ballpark for measuring pressure - its all you need for long range shooting.

!!!actually, that pressure looks like it might be corrected for sea level - will check back later!!!
 
Last edited:
Listen Mate Do This and only THIS

and I promise you will Learn what LowLight is Telling you You are making this far to hard for your self, OK

1) Turn OFF SYNC in the Baro Screen

2) Set REF ALT TO ZERO on the BARO Screen

3) Now go to the ALT Screen

4) Set the REF BARO to 29.92

5) in the ALT Screen make sure the SYNC is still turned of from when you Turned it OFF in the Baro Screen,

This is all you have to do,,,,DO NOT HAVE THESE TWO SCREENS SYNCED, what the weather is doing DOES NOT MATTER What Matters is Getting the Correct Readings for the Area you are shooting in,

With Your software App always set your Altitude to Zero when you are Zeroing your Rifle and put in the Current Station Pressure In The Zeroing Box

and when you go and shoot else where Then Put in the current station Pressure into the Current weather Box In Your App (NOT THE ZEROING BOX)

then ADD the TEMP,,,WIND ETC

FORGET SETTING THE ALT IN THE WEATHER BOX IN THE apps CURRENT WEATHER BOX,

LowLight has fired more shots that Ive had ***Ks so Stop making Life hard for your self, Now give it ago and tell us how you get On

good luck,,, John
 
Last edited:
The above is all correct. But I still recommend stopping by the airport to verify your unit is reading accurately against the one from the airport. If it's not then there's something wrong with your unit.
 
The above is all correct. But I still recommend stopping by the airport to verify your unit is reading accurately against the one from the airport. If it's not then there's something wrong with your unit.

Absolutely,,,, The AirPort Equipment is checked and double checked and it is the best way to find out if you gear is good to go,

John
 
Sorry Unknown,

We're all screaming the same message here...

As we're all saying, check the thing is giving you somewhat correct readings and start shooting. Living where you are, there's a lot of other things you can get more wrong than pressure.

In summary, if you are only interested in long range shooting, for weather conditions, it's only temp, pressure and humidity. Everything else is noise. And as John and Lowlight says the settings don't matter unless you need to accurately track altitude (like you are flying or something, but you'd already know this).

In fact not getting the correct sight height above the bore line can be a bigger issue for wrong ballistic solutions, unless you shoot and practice in Alpine regions (where pressure changes a lot).

Sent from my iPad using Tapatalk HD
 
So, I set up my user screen 1 on my Kestrel. I didn't mess with any of the factory settings. Altitude and pressure are referenced like they should be from the factory. Here's my user screen 1. Is this pretty much all I need to know for Shooter or AB?



Sent from my SM-N900V using Tapatalk
 
I put the same references on my screen 3 with another on screen 2 for wind, etc.My only question on yours is what your elevation is for a reading of 26.12"hg. Either you are on a mountain or something isn't right.
 
On Mine I have wind, Baro and Temp on my first screen as they are the most important conditions relative to Shooting

and on Screen two I have Humidity then Alt and the DA,,,,I just prefer to have them in order of importance,
so i am built for Speed.

john
 
Sounds about right for 3800'.
I run the baro/temp/humidity on #3 then baro/temp/wind on #2. I do it that way because I don't care much what the wind is doing where I am. But I rarely shoot inside of 750yd, & I'm always in the mountains shooting across valleys.
 
Sounds about right for 3800'.
I run the baro/temp/humidity on #3 then baro/temp/wind on #2. I do it that way because I don't care much what the wind is doing where I am. But I rarely shoot inside of 750yd, & I'm always in the mountains shooting across valleys.

I like that setup. It's nice to know wind speed for a reference, but nothing beats just learning how to read wind.

I cross checked the Kestrel altitude, with a GPS altitude app. They were only about 200ft difference.

Sent from my SM-N900V using Tapatalk
 
I would like to rehash this thread with a simple question. I have my baro ref set to "0 ft" as specified, and I have my Altitude ref set to "29.92 inHg" as specified. I'm in Baton Rouge, LA. It is telling me my current reading is "30.09 Hg", Altitude is -164', and Density Altitude is 1226'.

I assume these are pretty accurate readings? I know based on this thread that the Altitude reading is worthless if you just ref to 0, but I wanted to know if the 30.09Hg reading seems correct as well as the DA reading? Thanks in advance for any answers.
 
I would like to rehash this thread with a simple question. I have my baro ref set to "0 ft" as specified, and I have my Altitude ref set to "29.92 inHg" as specified. I'm in Baton Rouge, LA. It is telling me my current reading is "30.09 Hg", Altitude is -164', and Density Altitude is 1226'.

I assume these are pretty accurate readings? I know based on this thread that the Altitude reading is worthless if you just ref to 0, but I wanted to know if the 30.09Hg reading seems correct as well as the DA reading? Thanks in advance for any answers.

Yes that's correct, Only use it this way because it will be correct anywhere on the plant, don't over complicate things by thinking too much because the Kestrel is giving you the readings for where you are, So don't worry about what the weather Liars say because their readings are adjusted by Man and Not Nature and your bullet relies on Nature man has no say in the Bullets Flight,

Good Luck John
 
I would like to rehash this thread with a simple question. I have my baro ref set to "0 ft" as specified, and I have my Altitude ref set to "29.92 inHg" as specified. I'm in Baton Rouge, LA. It is telling me my current reading is "30.09 Hg", Altitude is -164', and Density Altitude is 1226'.

I assume these are pretty accurate readings? I know based on this thread that the Altitude reading is worthless if you just ref to 0, but I wanted to know if the 30.09Hg reading seems correct as well as the DA reading? Thanks in advance for any answers.

You got some thick air down there. Good for racing and making power, bad for shooting. Lol.

Sent from my SM-N900V using Tapatalk
 
Yes that's correct, Only use it this way because it will be correct anywhere on the plant, don't over complicate things by thinking too much because the Kestrel is giving you the readings for where you are, So don't worry about what the weather Liars say because their readings are adjusted by Man and Not Nature and your bullet relies on Nature man has no say in the Bullets Flight,

Good Luck John

I thought so. Thanks.
 
It's pretty simple, leave it to factory settings and don't change anything.

Reference Altitude to 0 that is in the Pressure screen

And Reference Pressure to 29.92 in the Altitude Screen

Those are the two you can change and what changes the values we are most concerned with.

This gives you Station Pressure and the Correct Density Altitude.

Do not set it to you location.

Do you sync either of the pressure or altitude? I have to turn sync off to get both numbers to stay in there. If I enable sync after changing the numbers they will both stay. I'm asking because my factory settings will not allow me to have both set references at the same time.

Listen Mate Do This and only THIS

and I promise you will Learn what LowLight is Telling you You are making this far to hard for your self, OK

1) Turn OFF SYNC in the Baro Screen

2) Set REF ALT TO ZERO on the BARO Screen

3) Now go to the ALT Screen

4) Set the REF BARO to 29.92

5) in the ALT Screen make sure the SYNC is still turned of from when you Turned it OFF in the Baro Screen,

This is all you have to do,,,,DO NOT HAVE THESE TWO SCREENS SYNCED, what the weather is doing DOES NOT MATTER What Matters is Getting the Correct Readings for the Area you are shooting in,

With Your software App always set your Altitude to Zero when you are Zeroing your Rifle and put in the Current Station Pressure In The Zeroing Box

and when you go and shoot else where Then Put in the current station Pressure into the Current weather Box In Your App (NOT THE ZEROING BOX)

then ADD the TEMP,,,WIND ETC

FORGET SETTING THE ALT IN THE WEATHER BOX IN THE apps CURRENT WEATHER BOX,

LowLight has fired more shots that Ive had ***Ks so Stop making Life hard for your self, Now give it ago and tell us how you get On

good luck,,, John
Here we go, sync off.
 
Last edited: