X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.4.51.92] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 5.0c6) with ESMTP id 784055 for flyrotary@lancaironline.net; Wed, 26 Oct 2005 11:05:15 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.4.51.92; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 26 Oct 2005 08:04:26 -0700 Message-ID: Received: from 4.171.174.180 by BAY107-DAV20.phx.gbl with DAV; Wed, 26 Oct 2005 15:04:26 +0000 X-Originating-IP: [4.171.174.180] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] EM2 Calibration Date: Wed, 26 Oct 2005 11:04:21 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00B9_01C5DA1D.04619D20" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Wed, 26 Oct 2005 11:04:21 -0400 X-OriginalArrivalTime: 26 Oct 2005 15:04:26.0646 (UTC) FILETIME=[8EAD0B60:01C5DA3E] This is a multi-part message in MIME format. ------=_NextPart_000_00B9_01C5DA1D.04619D20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Joe, Something not right here. The scale factor should not be negative. The = default value for oil pressure channel as shipped is +9.349. Making the = EM2 user calibratable so that a variety of sensors can be used is = obviously a mixed blessing and there is a limit on just how far from the = default sensor you can go. Are you using the recommended sensor or = something else? Try to stay with the 10 - 180 ohm (low to high) VDO = pressure sensor family. Trying to calibrate with an inverse sensor (low = pressure =3D high resistance) is theoretically possible using negative = scale factor but can be devilishly tricky to do. On temp sensor calibration, do not use a low value (like ice water) as = the low end calibration point. Automotive gauge sensors are not linear = or accurate down there. I typically use 100 - 130 deg. F as the low = end and boiling water as the upper point. Al's suggested use of an = infrared temp gauge to calibrate is a good one. =20 Tracy=20 ----- Original Message -----=20 From: Joe Hull=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 26, 2005 10:23 AM Subject: [FlyRotary] EM2 Calibration Thanx for all the suggestions on calibrating my EM2 -=20 I spent 3 hours last night trying to calibrate just the Oil Pressure = sender. Only about 30 minutes of that were real calibration tasks - the = rest of the time was spent trying to get a positive number instead of a = negative number. Anyone know why or how the "Scale Factor" is negative? = =20 If the "Scale Factor" is negative then the derived value, of course, = is negative. So, I tried to see if I could get the scale factor to "wrap = around" by bringing it to zero - but after hours of holding buttons and = countless counts to -63.99% (and or -128) I did nothing but overflow = onto the screen buffer and start popping numbers onto screen labels. So, = it was the same tedium getting it back to where it was. =20 There's got to be an easier way! =20 Thanx, Joe Hull Redmond (Seattle), Washington Cozy MkIV #991 (working on Engine & Electrical & Finishing) = http://www.maddyhome.com/canardpages/pages/JoeHull/index.html =20 ------=_NextPart_000_00B9_01C5DA1D.04619D20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Hi Joe,

Something not right here. The scale factor should not be=20 negative. The default value for oil pressure channel as shipped is = +9.349. Making the EM2 user calibratable so that a variety of = sensors can=20 be used is obviously a mixed blessing and there is a limit on = just how=20 far from the default sensor you can go. Are you using the = recommended=20 sensor or something else? Try to stay with the 10 - 180 ohm (low = to high)=20 VDO pressure sensor family. Trying to calibrate with an inverse = sensor=20 (low pressure =3D high resistance) is theoretically possible using = negative scale=20 factor but can be devilishly tricky to do.

On temp sensor calibration, do not use a low value (like ice water) = as the=20 low end calibration point. Automotive gauge sensors are not = linear or=20 accurate down there. I typically use 100 - 130 deg. F as the = low end=20 and boiling water as the upper point. Al's suggested use of an = infrared=20 temp gauge to calibrate is a good one.

Tracy

----- Original Message -----

From: Joe=20 Hull

To: Rotary motors in = aircraft

Sent: Wednesday, October 26, = 2005 10:23=20 AM

Subject: [FlyRotary] EM2=20 Calibration

Thanx for all=20 the suggestions on calibrating my EM2 =96 =

I spent 3 hours last = night trying=20 to calibrate just the Oil Pressure sender. Only about 30 minutes of = that were=20 real calibration tasks =96 the rest of the time was spent trying to = get a=20 positive number instead of a negative number. Anyone know why or how = the=20 =93Scale Factor=94 is negative? =20

If the =93Scale = Factor=94 is negative=20 then the derived value, of course, is negative. So, I tried to see if = I could=20 get the scale factor to =93wrap around=94 by bringing it to zero =96 = but after hours=20 of holding buttons and countless counts to -63.99% (and or -128) I did = nothing=20 but overflow onto the screen buffer and start popping numbers onto = screen=20 labels. So, it was the same tedium getting it back to where it=20 was.

There=92s got to be an = easier=20 way!

Thanx,

Joe=20 Hull

Redmond=20 (Seattle), Washington

Cozy = MkIV #991=20 (working on Engine & Electrical & = Finishing)

http://www.maddyhome.com/canardpages/pages/JoeHull/index.html

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