Forums: Skydiving: Gear and Rigging:
Altimeter problems

 


SpeedRacer  (B 26329)

May 7, 2001, 3:19 PM
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Altimeter problems Can't Post

OK I have a wrist altimeter that I bought used from a rigger. On Saturday I zeroed it on the ground. On the flight to altitude it seemed to be working OK. But when I got out, it seemed to be showing a lower altitude than it should have. At 4000 feet (according to the altimeter) I broke off & tracked away, pulling at what I thought was about 2800 feet. But when I looked around, it looked much higher than that. As time when on I became more sure, especially when it read zero just as I was flying downwind towards the beginning of my baseleg (at this point, of course, I was relying on my eyes, not my altimeter). And when I landed, it read my altitude as negative 900 feet!

This is an altimaster II, which is supposed to be a good altimeter. But I don't know, I'm a newbie (46 jumps). Anyone have similar problems? Strangely enough, when I re-zeroed it, I had no problems with the second jump of the day. Weird.


Speed Racer

Brew Skies



Stacy  (D License)

May 7, 2001, 3:54 PM
Post #2 of 6 (915 views)
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Re: Altimeter problems [In reply to] Can't Post

Chances are it just needs cleaned. A friend of mine had a wierd problem with hers and Alti II tested it, just needed taken apart and cleaned. Alti II would do this for you or I'm sure a rigger could. Just a guess. =c)

Stacy
http://astro.temple.edu/~sweeks


SkySlut  (D License)

May 7, 2001, 4:03 PM
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Re: Altimeter problems [In reply to] Can't Post

Yeah, its pretty cool to see them tested. I had mine tested in Florida by the Alti-guy. They put it in this little pressure chamber to simulate the different altitudes. Funny thing is...your altitude can be off at different altitudes. Mine was fine, but they do take them apart and fix them up for you. They did it for free there. I would ask around to see if anyone has one of these chambers. I dont know how common they are. Alti IIs are pretty hard to move the dial by accident, but that could have happened too. You never know. Just another reason to keep an eye on what you are rubbing up against in the plane...you never know what may shift or get knocked loose. Another good thing to do on the ground when you zero your altimeter out is to tap gently on the face of it to make sure that the needle isnt stuck in any weird position. That could have happened too, but 900 feet is a bit excessive. But if it works...it works. Keep an eye on it or ask a rigger to see if they have a pressure chamber kicking around.

-Slut

"I'll jump anything!"


weid14  (D 20292)

May 7, 2001, 4:43 PM
Post #4 of 6 (904 views)
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Re: Altimeter problems [In reply to] Can't Post

you could have also bumped it in the plane and caused the dial to turn. Be careful with all your equipment. I actually had that happen on a student jump I pulled way high cause the altitude read wrong. must have moved in the plane before exit. Check others altimeters against yours on the climb and before exit. They will all read a little different at different altitudes (new alti's will have how much it is off at various altitudes on a card), but should be in the ballpark.



<FONT SIZE=-1><EM>Edited by weid14 on 5/7/01 04:44 PM.</EM></FONT>


Zennie

May 7, 2001, 4:53 PM
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Re: Altimeter problems [In reply to] Can't Post

Besides calibrating on the ground, I usually try to verify my alti on the ride up when my audible gives its 1000 foot warning.


------------
Blue Skies!

Zennie


PalmettoTiger

May 7, 2001, 5:32 PM
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Re: Altimeter problems [In reply to] Can't Post

Wow. All of the suggestions about protecting it in the plane gave me a flashback to my last student jump when we were really crammed in there. I fished up a mental picture of the aircraft from inside -- and instantly my pulse doubled and my skin was covered with goosebumps.

What other activity (that you can discuss in polite company) gives you reactions like that!?! SKYDIVING RULES! CoolCool

Blues, squares,
PTiger



Forums : Skydiving : Gear and Rigging

 


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