X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 24 Dec 2010 14:30:06 -0500 Message-ID: X-Original-Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.123] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTP id 4652689 for lml@lancaironline.net; Thu, 23 Dec 2010 16:32:57 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.123; envelope-from=tednoel@cfl.rr.com X-Original-Return-Path: X-Authority-Analysis: v=1.1 cv=pepdxKapwHuwCZNFD5uob2wvham6E+RljB0uXw08FdQ= c=1 sm=0 a=TlWLetU4XqAA:10 a=5zEv8FOEouFFTgTFH6HffA==:17 a=3oc9M9_CAAAA:8 a=1oqGTYSLAAAA:8 a=Ia-xEzejAAAA:8 a=oCcaPWc0AAAA:8 a=fir9o2HoGIcm4gFTMqkA:9 a=3rlj1Xz_obu1tiz_YP0A:7 a=Z-xvAHifOml7-SlDpXLRDQrRxY4A:4 a=wPNLvfGTeEIA:10 a=CVU0O5Kb7MsA:10 a=U8Ie8EnqySEA:10 a=cvn8laQl214A:10 a=4PR2P7QzAAAA:8 a=Xe6f0MEEedZRFUrMxDgA:9 a=XY0VvDUU2ILLI3f-ZlsA:7 a=1wDNboJyooYHocVmtVYrdSnHbwcA:4 a=djSSOgbfo6cA:10 a=5zEv8FOEouFFTgTFH6HffA==:117 X-Cloudmark-Score: 0 X-Originating-IP: 97.101.50.108 Received: from [97.101.50.108] ([97.101.50.108:62471] helo=[192.168.0.102]) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id AD/87-19545-5EFB31D4; Thu, 23 Dec 2010 21:32:21 +0000 X-Original-Message-ID: <4D13BFE5.4050900@cfl.rr.com> X-Original-Date: Thu, 23 Dec 2010 16:32:21 -0500 From: Ted Noel User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101207 Lightning/1.0b2 Thunderbird/3.1.7 MIME-Version: 1.0 X-Original-To: Lancair Mailing List Subject: Re: [LML] Re: Revised Fuel Probe Calibration Map (after Six Years) References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------000500050800080007020207" This is a multi-part message in MIME format. --------------000500050800080007020207 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit I would doubt the earlier suggestion that the probe sagged, given that it's supported at every rib it passes through. It would seem that since the probe works by measuring capacitance, that something is coating the probe, changing its electrical value slightly. Perhaps fuel varnish? Ted Noel N540TF On 12/20/2010 8:52 AM, Sky2high@aol.com wrote: > Jeff, > I have had the EPI 800 system (pre VM1000) with the fuel computer per > VMS. There has been no degradation in fuel tank level readings since > 1996. > Scott Krueger > In a message dated 12/19/2010 6:09:57 P.M. Central Standard Time, > liegner@embarqmail.com writes: > > Lancair ListServ, > > FWIW: In my Lancair IVP, I have VMS fuel capacitance probes (AC > output) which interface with Pricnceton Electronics Interface > units (AC in, DC out) which communicates with my Chelton's EAU > (originally made by GRT). > I recently re-calibrated my fuel probes output through the > Princeton interface unit, as I wondered about calibration drift > after six+ years. Each tank holds 55 gallons, and the > step-reading system is based on 10% increments. > > > As you can see, the output reading has changed over time, > resulting in a display error in fuel volume in the tank. This > explains the calculated Totalizer mismatch (and WARNING message) > with the probe's Fuel Quantity reading, as occassionally seen on > long flights. An example is when there was actually 44 gallons in > the tank (ex, after using 11 gallons per fuel flow sensor), the > older fuel map told me there was 38.5 gallons...you can understand > the Totalizer error created by this. > > I simply post this in case others find it relevant or interesting. > > Jeff L in New Jersey > LIVP > > > -- > For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html > > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1170 / Virus Database: 426/3331 - Release Date: 12/22/10 > --------------000500050800080007020207 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit I would doubt the earlier suggestion that the probe sagged, given that it's supported at every rib it passes through. It would seem that since the probe works by measuring capacitance, that something is coating the probe, changing its electrical value slightly. Perhaps fuel varnish?

Ted Noel
N540TF

On 12/20/2010 8:52 AM, Sky2high@aol.com wrote:
Jeff,
 
I have had the EPI 800 system (pre VM1000) with the fuel computer per VMS.  There has been no degradation in fuel tank level readings since 1996.
 
Scott Krueger
 
In a message dated 12/19/2010 6:09:57 P.M. Central Standard Time, liegner@embarqmail.com writes:
Lancair ListServ,

FWIW:  In my Lancair IVP, I have VMS fuel capacitance probes (AC output) which interface with Pricnceton Electronics Interface units (AC in, DC out) which communicates with my Chelton's EAU (originally made by GRT).
 
I recently re-calibrated my fuel probes output through the Princeton interface unit, as I wondered about calibration drift after six+ years.  Each tank holds 55 gallons, and the step-reading system is based on 10% increments.


As you can see, the output reading has changed over time, resulting in a display error in fuel volume in the tank.  This explains the calculated Totalizer mismatch (and WARNING message) with the probe's Fuel Quantity reading, as occassionally seen on long flights.  An example is when there was actually 44 gallons in the tank (ex, after using 11 gallons per fuel flow sensor), the older fuel map told me there was 38.5 gallons...you can understand the Totalizer error created by this.

I simply post this in case others find it relevant or interesting.

Jeff L in New Jersey
LIVP

 

--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html


No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1170 / Virus Database: 426/3331 - Release Date: 12/22/10


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