Re: Thinking of purchasing a Garmin 276c

From: Dave Baker (newsgroup_poster_at_jodael.com)
Date: 11/25/04 

Date: Thu, 25 Nov 2004 17:42:15 +0800

On Wed, 24 Nov 2004 16:47:52 -0000, "Ivor Jones" <this.address@notvalid.inv>
wrote:

>I'd say immersion in 1m of water for up to 30 minutes qualifies as
>waterproof..? Granted, it's not designed for continuous underwater
>*operation* (that's IPX8) but good enough for the designation waterproof,
>surely..?

IP67 is "waterproof" when stuck 1m underwater for 30 minutes.

IP67 is not gas-tight. so humid air gets sucked in as the temperature rises
during the day. Later on the ambient temperature goes down, and the water
condenses out of the humid air, and now you have a few drops of water inside
your IP67 box/instrument. Keep this up for a week & you can get about 5mm of
water inside a very expensive Fibox IP67 box the size of a shoe-box.

So, "waterproof" doesn't mean it can't get water inside it. :-)

The solution in our case was to put a gore-tex pressure-compensation valve on
the box - once this was installed, there was no more pressure differential
between outside & inside, so no more air sucked into the box to bring water
vapour with it.

Dave

The email address used for sending these postings is not valid.
All replies to the group please.

Relevant Pages

  • Re: Politicians and energy policy
    ... there WILL be ingresion of humid air. ... The water heater comes on after midnight for about 1.5 hours, ... service changed their pricing to save consumers money if they ... If the high-demand hours cost more, ...
    (sci.electronics.design)
  • Re: humidity and hydroxyl radical
    ... Nowhere can I find any reference that indicates that water ... > that there are radicals formed from the water vapor, ... > support the notion that water vapor will form hydroxyl radicals without ... Humid air is not a much better conductor of electricity. ...
    (sci.chem)
  • Re: Source Sealed Potentiometers?
    ... IP 67 is flush water, ... I think I might be able to get away with IP67. ... I need to be able to measure an angle 0-360, ...
    (comp.arch.embedded)