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 imr-ma03.mx.aol.com ([64.12.206.41] verified) by logan.com (CommuniGate Pro SMTP 5.3.0) with ESMTP id 4067085 for lml@lancaironline.net; Wed, 06 Jan 2010 14:41:50 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.206.41; envelope-from=Sky2high@aol.com Received: from imo-ma01.mx.aol.com (imo-ma01.mx.aol.com [64.12.78.136]) by imr-ma03.mx.aol.com (8.14.1/8.14.1) with ESMTP id o06JfAx9021086 for ; Wed, 6 Jan 2010 14:41:10 -0500 Received: from Sky2high@aol.com by imo-ma01.mx.aol.com (mail_out_v42.5.) id q.c49.530e3e38 (34919) for ; Wed, 6 Jan 2010 14:41:06 -0500 (EST) Received: from smtprly-de03.mx.aol.com (smtprly-de03.mx.aol.com [205.188.249.170]) by cia-da03.mx.aol.com (v127.7) with ESMTP id MAILCIADA034-b2504b44e747112; Wed, 06 Jan 2010 14:41:05 -0500 Received: from magic-m16.mail.aol.com (magic-m16.mail.aol.com [172.21.188.208]) by smtprly-de03.mx.aol.com (v127.7) with ESMTP id MAILSMTPRLYDE035-b2504b44e747112; Wed, 06 Jan 2010 14:40:55 -0500 From: sky2high@aol.com X-Original-Message-ID: <3a616.5e969c25.38764147@aol.com> X-Original-Date: Wed, 6 Jan 2010 14:40:55 EST Subject: Re: [LML] Re: Fuel Planning - Capacitance probes X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_3a616.5e969c25.38764147_boundary" X-Mailer: AOL 9.5 sub 155 X-AOL-ORIG-IP: 67.175.242.202 X-AOL-IP: 172.21.188.208 X-Spam-Flag:NO X-AOL-SENDER: Sky2high@aol.com --part1_3a616.5e969c25.38764147_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Mike, 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? The VM fuel system uses a regulated 5 VDC. The variation due to voltage is not relevant with that system. Grayhawk In a message dated 1/6/2010 8:51:56 A.M. Central Standard Time, mikeeasley@aol.com writes: 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://chevronglobalaviation.com/docs/aviation_tech_review.pdf) _http://www.gewater.com/industries/refining_fuel/fuel_additives/dehazers.jsp _ (http://www.gewater.com/industries/refining_fuel/fuel_additives/dehazers.jsp) Mike Easley Colorado Springs --part1_3a616.5e969c25.38764147_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Mike,
 
If we calibrate our probes with the engin= e off, at=20 ~12V in my airplane, how would the fuel level readings change in flight wi= th=20 ~13.8V in the electrical system?
 
The VM fuel system uses a regulated 5 VDC.  The variation= due=20 to voltage is not relevant with that system.
 
Grayhawk
 
In a message dated 1/6/2010 8:51:56 A.M. Central Standard Time,=20 mikeeasley@aol.com writes:
Gary,
 
Since the capacitance probes seem to be= fairly=20 reliable in our small sampling, but the potential for=20 inaccuracies is there, I'm curious about a couple things.
 
If we calibrate our probes with the eng= ine off,=20 at ~12V in my airplane, how would the fuel level readings change in flig= ht=20 with ~13.8V in the electrical system?
 
How much does temperature effect the fu= el level=20 readings?  Say from 30F to 80F.
 
Also, I did some digging on water being= dissolved=20 in 100LL.  It appears that they have an additive that causes dissol= ved=20 water to separate from the fuel and collect at the bottom of the storage= =20 container (at any step along the way including our wing tanks).  I= hate=20 to use the word "practical" when talking to an engineer, but from a prac= tical=20 sense how much water can we have dissolved in our 100LL?  And is th= is a=20 bigger problem for the turbine guys?
 
 
 
Mike Easley
Colorado=20 Springs
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