X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 07 Apr 2007 12:32:34 -0400 Message-ID: X-Original-Return-Path: Received: from mta11.adelphia.net ([68.168.78.205] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 1972668 for lml@lancaironline.net; Sat, 07 Apr 2007 09:04:42 -0400 Received-SPF: pass receiver=logan.com; client-ip=68.168.78.205; envelope-from=glcasey@adelphia.net Received: from [75.82.254.207] by mta11.adelphia.net (InterMail vM.6.01.05.02 201-2131-123-102-20050715) with ESMTP id <20070407130354.LNTD22297.mta11.adelphia.net@[75.82.254.207]> for ; Sat, 7 Apr 2007 09:03:54 -0400 Mime-Version: 1.0 (Apple Message framework v752.2) In-Reply-To: References: Content-Type: multipart/alternative; boundary=Apple-Mail-10-75336788 X-Original-Message-Id: <8BA908CD-D09D-44FA-821F-EADD1FDE2633@adelphia.net> From: Gary Casey Subject: Re: Testing for fuel leaks and fuel probes to use X-Original-Date: Sat, 7 Apr 2007 06:03:52 -0700 X-Original-To: "Lancair Mailing List" X-Mailer: Apple Mail (2.752.2) --Apple-Mail-10-75336788 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Turns out we build pressure sensors that are used for measuring fluid level (the most fun one is for the sewage holding tank on the Airbus 320). Unfortunately, there are lots of problems with using this method for fuel level. One is that the pressure is relatively low - if the full fuel level is 1 foot above the sensor the pressure is only about 0.4 psi, so you need a fairly low pressure sensor, but that's not too bad. The sensor needs to be vented and it should be vented to the vapor in the tank just in case the tank vent system isn't perfect, and most Lancair system aren't because the vent is pointed forward, slightly pressurizing the tank. However, if any liquid fuel gets in the vent the accuracy is destroyed - and maybe the sensor as well. Also, the pressure sensor would presumably be located at the wing root, so there would be substantial errors induced caused by out-of-level conditions (slips). And, of course, the sensor has to be compatible with liquid gasoline. I have been playing around with just such a device that can be used for checking fuel level during a preflight, especially useful on a low-wing plane where the dipstick doesn't always reach the fuel. I rigged up a pressure sensor with a fitting that can be pushed against the quick-drain and it will read fuel level, either by displaying a pressure number, or actual fuel quantity by calibrating it for the specific airplane. A few details need to be sorted out, but it can be made to be fairly accurate; within about 1 percent. If the plane is parked where it isn't level there would be an error, but that condition isn't the norm. And there is no problem with venting the sensor to atmosphere as the tank shouldn't be pressurized while standing still. What I don't know is whether anyone would be willing to buy such a thing (probably about $100). Might be a good stocking stuffer for the pilot who has everything else. Any potential interest? Gary Casey N224SG > > From: "Mark Steitle" > Date: April 5, 2007 6:38:53 AM PDT > To: lml@lancaironline.net > Subject: Re: [LML] Re: Testing for fuel leaks and fuel probes to use > > > Bryan, > I heard of one builder that used pressure sensors as fuel level > sensors. I think they were rated at 0-5psi. Sounds like this may > be a solution for you too. > > Mark S. > --Apple-Mail-10-75336788 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=ISO-8859-1 Turns out we build pressure = sensors that are used for measuring fluid level (the most fun one is for = the sewage holding tank on the Airbus 320).=A0 Unfortunately, there are = lots of problems with using this method for fuel level.=A0 One is that = the pressure is relatively low - if the full fuel level is 1 foot above = the sensor the pressure is only about 0.4 psi, so you need a fairly low = pressure sensor, but that's not too bad.=A0 The sensor needs to be = vented and it should be vented to the vapor in the tank just in case the = tank vent system isn't perfect, and most Lancair system aren't because = the vent is pointed forward, slightly pressurizing the tank. =A0However, = if any liquid fuel gets in the vent the accuracy is destroyed - and = maybe the sensor as well. =A0Also, the pressure sensor would presumably = be located at the wing root, so there would be substantial errors = induced caused by out-of-level conditions (slips). =A0And, of course, = the sensor has to be compatible with liquid gasoline.

I have been playing around = with just such a device that can be used for checking fuel level during = a preflight, especially useful on a low-wing plane where the dipstick = doesn't always reach the fuel. =A0I rigged up a pressure sensor with a = fitting that can be pushed against the quick-drain and it will read fuel = level, either by displaying a pressure number, or actual fuel quantity = by calibrating it for the specific airplane. =A0A few details need to be = sorted out, but it can be made to be fairly accurate; within about 1 = percent.=A0 If the plane is parked where it isn't level there would be = an error, but that condition isn't the norm. =A0And there is no problem = with venting the sensor to atmosphere as the tank shouldn't be = pressurized while standing still. =A0What I don't know is whether anyone = would be willing to buy such a thing (probably about $100). =A0Might be = a good stocking stuffer for the pilot who has everything else.=A0 Any = potential interest?

Gary = Casey

N224SG

From: = "Mark Steitle" <msteitle@gmail.com>
=
Date: April 5, 2007 6:38:53 AM = PDT
To: lml@lancaironline.net
Subject: Re: [LML] Re: Testing for fuel leaks = and fuel probes to use

=
Bryan,

I heard of one builder that used pressure = sensors=A0as fuel level sensors.=A0 I think they were rated at 0-5psi.=A0 = Sounds like=A0this may be a solution for you too.

=A0
=
Mark S.

= --Apple-Mail-10-75336788--