Poor man's barometer? Also would like some of your dope...

jeffl838

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Feb 20, 2013
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What's the best option for measuring barometric pressure on a budget? Would like to shoot out to a mile. I figure temperature will be easy enough with a thermometer. Not too worried about humidity.

Also, if you wouldn't mind, I'd like to see some dope that you guys have gathered. Specifically for a 26" 1/12 308 w/ 168 SMK and for a Savage 12 LRP in 6.5cm w/ 140 amax. Thanks.
 

Dogtown

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Jet Boil and a stopwatch? Measuring the speed at which water boils is how we humans measured air pressure for centuries.
 

jeffl838

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Haha I'll keep that in mind if I can't find anything more economical than a kestrel. Would also like recommendations for a decently priced LRF.
 
M

milo 2.0

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If you do buy a Kestrel, get one that gives Density Altitude, and use it. A cell phone and a call to a local radio station for a weather update may work.

I f they get pissy with you, tell them you're a high school student working on a sceince project involving hot air balloon flight and you'd just as soon not land in Russia.
 
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P7id10t

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Dallas Semiconductor / Maxim has (or used to) this sensor the size of two nickles sandwiched together that will give you RH, temperature (to 0.1 °C) and pressure. It has its own battery which lasts a few years and you can read it with a PC (perhaps even a phone by now)
Cost was $50 last time I used one. Very accurate- we checked ours against calibrated Viasala meters.
 

TwoNiner

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I was in the same boat. I bought a casio pathfinder watch that has a barometer and temperature guage in it. The barometer seems to work but the temp guage doesn't seem to be accurate.
 

Biggerhammer50

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What kind of cell phone do you have? A Samsung Galaxy S3 has a built in barometer. All you have to do is download the app to use it.

"ΜΟΛΩΝ ΛΑΒΕ"
 

ScottyD

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I just picked up one of these for $42.50. Happy with it so far. All I needed was temp and barometric pressure this things seems to fit the bill nicely:

High Gear WeatherPort Altimeter Barometer

I've got some 140g A-max (~2825fps) dope for you in mils. 25" barrel and data collected at around 5000ft (60 degrees and 25.00 InHG)

100yds: 0
200yds: .5
300yds: 1.0
400yds: 1.7
500yds: 2.5
600yds: 3.4
700yds: 4.3
800yds: 5.4
900yds: 6.5
1000yds: 7.6
 

carp

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Downloaded Nikon Spot On app for my Iphone. It has a button to "get current conditions" based on your GPS location. Gives you Baro, elevation, temp, humidity, GPS Datum, and windspeed for your current location. Seems pretty accurate. Not sure where it pulls its info from.
 

1spot

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I would be careful of using weather forcast or reports to get baro pressure. Alot of the time they are giving you the average air pressure for a given location - at sea level. If you want to use it accurately you need to use a handheld device at your location for what is refered to as station pressure. I use a leica 1600 crf rangefinder for station pressure.