How to very accurately predict your pressure with temp. No more guessing!!!

[D-R0CK]

This is how to predict what your pressure will be when the weather changes. Wondered if anyone else would enjoy/use this, or perhaps print out the simplified version shown below the numbered explanation and example I wrote (tape to a fill tank maybe?)
Many members on this forum use HPA or have a PCP gun. They ought to know this simple equation:
1) When you fill your tank, take the temp of your location in degrees Celsius and add 273 (this is the temp in Kelvins) also, record your fill pressure.
2) To find your pressure at any given time, just divide the new temp (again in Kelvins) by the temp you filled it at, and then multiply by your initial fill pressure!
For example: I have a tank that I fill to 2000psi while it’s 10 degrees Celsius. Then, I want to know what the pressure will be in the afternoon, when the weatherman says it will be 25 degrees Celsius. I take 10 and add 273 to get 283, and then divide 2000psi by 283 degrees Kelvin to get 7.07 (psi of pressure per degrees Kelvin) next; you find that 25 degrees Celsius is 298 degrees Kelvin (273+25) and 298 degrees times 7.07 psi gives me a predicted 2106 psi in the afternoon.
I hope this is useful to anyone who uses HPA! I'm not sure if it will work on C02, since I believe it condenses into a liquid in the capsules at pressures high enough to be really useful.
(Initial temp in C) + 273 = X
(New/Future temp in C) + 273 = Y
((Initial fill pressure)/(X)) x (Y) = new (or future) pressure.
Hope someone finds this useful  especially for competition shooting.

[quickster47 †]

Good information and a handy mathematical way to figure your pressure when the weather changes.

Thanks for posting this.

Carl

Edited for spelling.

[1377x]

if you are lazy or not good at math you could use one of these calculators also
http://www.airgunhome.com/pages/calculators.html