Kestrel Density Altitude issues

[Autark]

I took my new Kestrel 4500 out to the range and tried to start recording some data for the day. The density altitude kept wandering, no matter what I did. There was a slight breeze and I held the unit steady at arms length. The numbers either kept climbing or falling alternately.

Just did the same thing in the house, set the unit down for about 10 minutes to see if it would stabilize. Same thing, number just kept climbing slowly.

Any thoughts on what might be the issue?

 

[-Snyper-]

Re: Kestrel Density Altitude issues

When you mean climbing, Give us some numbers to go by. Start with lowest, and where did it stop.
DA does change quite often, so that is normal. That's why i depend on my kestrel for dope.

 

[Autark]

Re: Kestrel Density Altitude issues

Just popped it open to have a look. Started at 2170 when I opened it up. After letting it sit for a while all on it's own, it fell down to 2130-2117 after 3 minutes, jumping from 2100 to 2070 after 5 minutes. It's fluctuating about 3-7 feet fairly constantly.

 

[Macdaddy]

Re: Kestrel Density Altitude issues

As I understand it, DA is based on air pressure so if yours varies slightly it would be from pressure changes in the atmosphere. Your changes seem fairly minor.

Others may have more expertise (I'm sure they do) but I don't see a real issue here.

 

[Tburkes]

Re: Kestrel Density Altitude issues

Go to any online ballistic computer and input different DA's and see how it changes the dope calculations.

You'll find that you're worrying about nothing with the fluctuations you're talking about.

 

[Trigger Monkey]

Re: Kestrel Density Altitude issues

As the others have said it's pretty normal for the displayed value to vary a little bit due to temperature and pressure changes. Since the DA value is take from the temperature, station pressure, and humidity it will fluctuate a little as the day goes on however it seems you had a pretty consistent 2100' DA.

 

[Autark]

Re: Kestrel Density Altitude issues

Thanks for the input. I guess I'll just average it and go from there.

 

[Lowlight]

Re: Kestrel Density Altitude issues

You don't use exact numbers for DA, you can round it to the nearest 500ft even the nearest 1000 ft.

Because DA is a combination of Barometric Pressure, Temperature, and Humidty the unit will fluctuate as the unit is recording micro changes in one of those factors.

DA is a field expedient method which is why I recommend using the specific inputs and not DA with a ballistic calculator. DA is a one number you can use in place of the long form method of recording everything.

 

[Autark]

Re: Kestrel Density Altitude issues

Got it, that is really helpful. Thanks again!

 

[fw707]

Re: Kestrel Density Altitude issues

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tburkes</div><div class="ubbcode-body">Go to any online ballistic computer and input different DA's and see how it changes the dope calculations.

You'll find that you're worrying about nothing with the fluctuations you're talking about. </div></div>

My Kestrel 4000 shows a small variation all the time, but it never seems to change my dope even .1 mil at 1000 yards.

 

[jaxfreebird]

Re: Kestrel Density Altitude issues

Newbie question here... You bring up a point that is something I have been wondering for a while. If it is better to input all of the individual factors (temp, press, humidity...) in the long form for ballistic calculators as opposed to using DA. Why spend the extra money on a Kestrel 4000 or 4500? Why not just get a more basic model 2500? Isn't the DA reading the biggest difference between the $350 Kestrels and the $150 versions?

 

[BigJohn141]

Re: Kestrel Density Altitude issues

You can use the models with less bells and whistles and be just fine. Using DA is simply a faster way of doing it with slightly less accurate results. Lets say you were hunting in a area with large elevation changes or during a weather change, you would have to re enter all the temp, humidity, and baro info to get a new shooting dope or you could punch in a single number.

 

[SRSDriver]

Re: Kestrel Density Altitude issues

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Autark</div><div class="ubbcode-body">Thanks for the input. I guess I'll just average it and go from there. </div></div>

That jump isn't big enough to change you dope. If it was jumping from 2000 to 3000, that would be a jump.