HoldtheIce 0 #1 September 28, 2009 We all use barometric pressure altimeters, right? I was thinking, what is the difference in barometric pressure in Millibars between say 13 thousand feet and ground level. I know there are variables. I’m just looking for a ballpark figure. Normal barometric pressure on average days here at ground level in my DZ is about 29.5 MB. Thanks All ~HoldCause they know, and so do I, The high road is hard to find A detour to your new life, Tell all of your friends goodbye Quote Share this post Link to post Share on other sites
Hellis 0 #2 September 28, 2009 this is what i got from my pro-track on a jump. the numbers is supposed to be Mbar*10 ground pressure that day was 1.005 Mbar. i dont know how that would add up with all the other numbers but thtas what pro-track tells me. it logs 4 times per second, and the first two seconds (8 logs) is before exit. so it starts loging before i exit the plane. exit altitude was 3900 meters and deployment happend at 700 meters. 61 seconds freefall time. hope this helps you6186 6186 6186 6186 6186 6186 6185 6188 6191 6194 6197 6201 6207 6211 6216 6220 6227 6233 6239 6245 6252 6260 6266 6272 6281 6293 6305 6319 6334 6349 6364 6377 6392 6409 6425 6440 6455 6472 6490 6508 6526 6544 6559 6575 6591 6606 6621 6636 6650 6662 6674 6686 6697 6707 6718 6730 6741 6748 6759 6770 6779 6788 6796 6804 6810 6818 6828 6838 6848 6859 6869 6880 6890 6902 6916 6928 6940 6952 6963 6972 6982 6996 7005 7014 7024 7035 7046 7057 7068 7080 7091 7101 7112 7122 7134 7146 7160 7172 7182 7193 7205 7216 7230 7243 7256 7268 7281 7295 7308 7324 7339 7355 7369 7382 7396 7411 7426 7440 7453 7466 7480 7493 7506 7521 7534 7547 7561 7574 7586 7600 7614 7629 7642 7652 7665 7677 7690 7703 7717 7728 7740 7755 7769 7780 7790 7802 7814 7826 7838 7852 7864 7876 7890 7900 7912 7922 7932 7945 7956 7968 7981 7995 8008 8023 8038 8050 8062 8076 8090 8103 8116 8130 8143 8156 8171 8185 8198 8213 8226 8239 8254 8267 8277 8290 8302 8314 8325 8336 8348 8360 8373 8388 8403 8418 8434 8449 8462 8474 8485 8499 8512 8526 8540 8554 8567 8582 8600 8617 8633 8648 8664 8680 8694 8708 8723 8738 8755 8770 8782 8793 8811 8830 8849 8865 8880 8899 8917 8933 8951 8967 8982 8997 9010 9025 9039 9054 9070 9085 9100 9114 9126 9138 9151 9165 9175 9182 9189 9200 9209 9213 9221 9230 9235 9241 9247 9253 9259 9263 9267 9270 9273 9276 9277 9278 9281 9282 9284 9285 9286 9287 9289 9289 9290 9291 9291 9291 9291 9291 9291 Quote Share this post Link to post Share on other sites
bfilarsky 0 #3 September 28, 2009 On a standard day, sea level pressure is 29.92 InHg. You lose 1" per thousand feet in the lower atmosphere, which would include 13,000'. So, you should expect roughly 17 InHg at 13,000 ft MSL. That would be 1.013 Bar at sea level, .57 Bar at 13,000'. Edit - you are confusing millibar with InHg (Inches of Mercury). Standard pressure at your DZ would be 29.5 InHg, not millibar. Quote Share this post Link to post Share on other sites
HoldtheIce 0 #4 September 28, 2009 Thanks for the reply, that works for me. Yes I did confuse InHg to Millibars. My barometer has both scales and I looked at it wrong. What got me thinking, is my altimeter moves all the time. I zeroed it out on Saturday for my jumps. Now it reads 820 feet. The barometric pressure is changing here. It's falling. We have a storm front coming in from the coast. I now understand the direct relationship of my altimeter and my barometer on the wall. The lower the pressure, the more feet applied onto my altimeter. Thanks, and Blue Skys ~HCause they know, and so do I, The high road is hard to find A detour to your new life, Tell all of your friends goodbye Quote Share this post Link to post Share on other sites
mjosparky 3 #5 September 30, 2009 This might help. SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites
riggerpaul 1 #6 September 30, 2009 can you post that file as something that is more universally readable? A text file? A PDF? Quote Share this post Link to post Share on other sites
phantomII 36 #7 September 30, 2009 Here you go. Quote Share this post Link to post Share on other sites
ryoder 1,382 #8 September 30, 2009 Quotecan you post that file as something that is more universally readable? A text file? A PDF? OpenOffice is free and handles that file nicely."There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones. Quote Share this post Link to post Share on other sites
JohnMitchell 14 #10 September 30, 2009 Quote I zeroed it out on Saturday for my jumps. Now it reads 820 feet. The barometric pressure is changing here. It's falling. We have a storm front coming in from the coast. That's a hell of a storm coming, maybe 70 points on the barometer. Just remember that high pressure forces the needle "down" (lower) on your altimeter, and low pressure moving in sucks it up. Quote Share this post Link to post Share on other sites
mjosparky 3 #11 September 30, 2009 Quotecan you post that file as something that is more universally readable? A text file? A PDF? I think it is a MS word doc. But I do like it better as a PDF file. SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites
