Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 3.4.5) with ESMTP id 772097 for rob@logan.com; Tue, 01 May 2001 18:34:20 -0400 Received: from luke.cpl.net ([63.169.72.3]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71175U5500L550S0V35) with ESMTP id com for ; Tue, 1 May 2001 17:27:54 -0400 Received: from [192.168.0.2] (137-18.red-dsl.cpl.net [192.216.137.18] (may be forged)) by luke.cpl.net (8.9.3/8.9.3) with ESMTP id OAA58324 for ; Tue, 1 May 2001 14:34:28 -0700 (PDT) User-Agent: Microsoft-Outlook-Express-Macintosh-Edition/5.02.2022 Date: Tue, 01 May 2001 14:34:28 -0700 Subject: Altitude sensor From: Hal Woodruff To: Message-ID: In-Reply-To: <20010501054706.AAA29490@pop3.olsusa.com> Mime-version: 1.0 Content-type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Hi All, Here's what I've got on the altitude sensor. I've found one that is a pressure sensor that goes off at 4.7 psi. This is the pressure difference between sea level and 10000 feet. When hooked to a "sea level" pressure reservoir the switch is activated when the reservoir exceeds ambient pressure by 4.7 psi. I took this up to altitude in a friend's RV6 and it actually switched at 10,300 ft. Switching off occurred at approx. 8500 ft. This is totally acceptable for my purposes of turning on/off a warning light. I'll have two in my plane: one for fuel pump reminder mounted in the gear box area, and one for cabin altitude warning mounted somewhere behind the panel. This will warn of cabin altitudes higher than 10,000 ft. alerting me of potential problem with pressurization system. The price of the switch is $30 including shipping. I can also assemble the reservoir assembly for an additional $5.00. The reservoir is a couple of PVC and brass fittings. The switch is a SPDT. Let me know if you're interested at woodruff@swefco.com. We'll need to order 20 as a minimum. I currently have promises on 9 switches - only 11 to go. I'll do this like I did the foam last summer by buying the lot and then sending it out to all. Contact me for a picture of the switch with the reservoir attached. Hal Woodruff >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>