From owner-freebsd-hardware Tue Oct 15 11:01:25 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id LAA24603 for hardware-outgoing; Tue, 15 Oct 1996 11:01:25 -0700 (PDT) Received: from Rigel.orionsys.com (root@rigel.orionsys.com [205.148.224.9]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id LAA24596 for ; Tue, 15 Oct 1996 11:01:22 -0700 (PDT) Received: from localhost (dbabler@localhost) by Rigel.orionsys.com (8.7.6/8.6.9) with SMTP id LAA20118 for ; Tue, 15 Oct 1996 11:01:20 -0700 (PDT) Date: Tue, 15 Oct 1996 11:01:20 -0700 (PDT) From: Dave Babler To: freebsd-hardware@freebsd.org Subject: Re: sticky drives (was: your mail) In-Reply-To: <199610150419.NAA18931@genesis.atrad.adelaide.edu.au> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-hardware@freebsd.org X-Loop: FreeBSD.org Precedence: bulk On Tue, 15 Oct 1996, Michael Smith wrote: > Dave Babler stands accused of saying: > > > This is absolutely true, dropping a drive below 0 deg C is a sure fire > > > way to damage it. Even the non-operating temp spec on almost all mfg's > > > disk is +5 C on the lower end. Having done MIL-SPEC drive work that > > > had to operate over -55 to +125 C the actual hardest part of this range > > > was the -5 to +5 C range, condensation being a real killer. > > > > Isn't the chamber where the platters reside hermetically sealed? If so, > > how would moisture be there to condense in the first place? > > Firstly; no, the chamber is often not sealed. If you pull a drive > apart you will often notice that there's a breather port with a bit of > filter material stuck over it. Many drives will have some silica gel > in them as well to help keep the humidity down. I've seen that, but the one I examined looked more like a pressure relief port. > Secondly, the drives are usually assembled in rooms with some nominal > amount of air humidity, so that even if the unit were sealed, there would > still be moisture inside. > Ah, should've figured that... I was harboring the illusion that they were purged with dried argon or something . Thanks for the info, guys! -Dave