X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 06 Jan 2010 16:15:37 -0500 Message-ID: X-Original-Return-Path: Received: from elasmtp-dupuy.atl.sa.earthlink.net ([209.86.89.62] verified) by logan.com (CommuniGate Pro SMTP 5.3.0) with ESMTP id 4066760 for lml@lancaironline.net; Wed, 06 Jan 2010 10:25:24 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.62; envelope-from=panelmaker@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=P6NZ1M2ALuvQvl8hSvcIXLHpnOK3sQYvRQEY0rnlkoF5ZX/jVGrGqvqsxvGZjKc6; h=Received:From:To:References:Subject:Date:Message-ID:MIME-Version:Content-Type:X-Mailer:X-MimeOLE:Thread-Index:In-Reply-To:X-ELNK-Trace:X-Originating-IP; Received: from [209.173.71.128] (helo=DELL8300) by elasmtp-dupuy.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1NSXke-0008S6-7g for lml@lancaironline.net; Wed, 06 Jan 2010 10:24:48 -0500 From: "Jim Nordin" X-Original-To: "'Lancair Mailing List'" References: Subject: Fuel Planning - Capacitance probes X-Original-Date: Wed, 6 Jan 2010 09:24:56 -0600 X-Original-Message-ID: <3F60A3C6EE814D38A7E8378CC65BE397@DELL8300> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0086_01CA8EB2.1CA022A0" X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Thread-Index: AcqO39JDd6gYae05QkKS4AlZEL7FyQAAu83A In-Reply-To: X-ELNK-Trace: bdfc62829fd2a80cc8ad50643b1069f8239a348a220c2609c96b4ab1888d4d6129351fad9372566e666fa475841a1c7a350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 209.173.71.128 This is a multi-part message in MIME format. ------=_NextPart_000_0086_01CA8EB2.1CA022A0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Mike, good question about the calibration of the probes at ~12v. with no charging going on. My sky sports probes in my LongEZ were quite a bit off . so much in fact the mfg sent me a chip to cure the problem without charge. I don't have my LNC2 operational yet so can't do the test. But that's a good question, the answer to which should be determined. Saying that, it might be a "relative" answer. Like they say, the important time to know your fuel quantity is when you are close to not having any. That was exactly the problem with the sky sports units. Idle the quantity was calibrated to zero and in the air it showed more when in fact it was empty. Not the best. I did not learn the hard way but probed the tank showing fuel when I arrived at a distant destination and the physical probe had no fuel on it. Scary. Jim _____ From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of mikeeasley Sent: Wednesday, January 06, 2010 8:51 AM To: lml@lancaironline.net Subject: [LML] Re: Fuel Planning - Capacitance probes Gary, Since the capacitance probes seem to be fairly reliable in our small sampling, but the potential for inaccuracies is there, I'm curious about a couple things. If we calibrate our probes with the engine off, at ~12V in my airplane, how would the fuel level readings change in flight with ~13.8V in the electrical system? How much does temperature effect the fuel level readings? Say from 30F to 80F. Also, I did some digging on water being dissolved in 100LL. It appears that they have an additive that causes dissolved water to separate from the fuel and collect at the bottom of the storage container (at any step along the way including our wing tanks). I hate to use the word "practical" when talking to an engineer, but from a practical sense how much water can we have dissolved in our 100LL? And is this a bigger problem for the turbine guys? http://chevronglobalaviation.com/docs/aviation_tech_review.pdf http://www.gewater.com/industries/refining_fuel/fuel_additives/dehazers.jsp Mike Easley Colorado Springs ------=_NextPart_000_0086_01CA8EB2.1CA022A0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Mike, good question about the = calibration of the probes at ~12v. with no charging going on. My sky sports probes = in my LongEZ were quite a bit off … so much in fact the mfg sent me a = chip to cure the problem without charge. I don’t have my LNC2 operational = yet so can’t do the test. But that’s a good question, the answer to = which should be determined.

Saying that, it might be a = “relative” answer. Like they say, the important time to know your fuel quantity is = when you are close to not having any. That was exactly the problem with the = sky sports units. Idle the quantity was calibrated to zero and in the air it = showed more when in fact it was empty. Not the best. I did not learn the hard = way but probed the tank showing fuel when I arrived at a distant destination and = the physical probe had no fuel on it. Scary.

Jim

 

From: = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of mikeeasley
Sent: Wednesday, January = 06, 2010 8:51 AM
To: = lml@lancaironline.net
Subject: [LML] Re: Fuel = Planning - Capacitance probes

 

Gary,

 

Since the capacitance probes seem to be fairly = reliable in our small sampling, but the potential for inaccuracies is = there, I'm curious about a couple things.

 

If we calibrate our probes with the engine off, at = ~12V in my airplane, how would the fuel level readings change in flight with = ~13.8V in the electrical system?

 

How much does temperature effect the fuel level readings?  Say from 30F to 80F.

 

Also, I did some digging on water being dissolved in 100LL.  It appears that they have an additive that causes dissolved = water to separate from the fuel and collect at the bottom of the storage = container (at any step along the way including our wing tanks).  I hate to = use the word "practical" when talking to an engineer, but from a = practical sense how much water can we have dissolved in our 100LL?  And is = this a bigger problem for the turbine guys?

 

 

 

Mike Easley

Colorado Springs

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