Return-Path: <13brv3@bellsouth.net> Received: from imf17aec.mail.bellsouth.net ([205.152.59.65] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3083828 for flyrotary@lancaironline.net; Wed, 17 Mar 2004 20:33:11 -0500 Received: from rad ([68.221.170.60]) by imf17aec.mail.bellsouth.net (InterMail vM.5.01.06.08 201-253-122-130-108-20031117) with ESMTP id <20040318013308.TLVC15240.imf17aec.mail.bellsouth.net@rad> for ; Wed, 17 Mar 2004 20:33:08 -0500 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: EGT/CHT wiring Date: Wed, 17 Mar 2004 19:31:09 -0600 Message-ID: <00da01c40c88$b0d52220$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00DB_01C40C56.663AB220" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_00DB_01C40C56.663AB220 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Tracy, Thanks for the clarification. I plan on making my own CHT thermocouples = by tig welding one end of J-type thermocouple wire and inserting into a = 1/8" hole in the rotor housing. What method would you suggest to keep the sensing end from shorting once inserted into the rotor housing? Would = 1/16" shrink tubing work? Mark S. =20 =20 I talked to Tracy about this today, mostly because I made all those = J-type thermocouples by just connecting the ends of the wire, but realized that they aren't grounded, and I didn't ground them inside the connector = either. Tracy suggested grounding them at the junction instead. My reply was something like "I don't see how you could generate a voltage when you're grounding the connection of the two wires". His reply was to look at a spark plug type CHT probe and notice that they're doing the exact same thing. I sure can't explain it, but it must work. =20 =20 I have yet to thoroughly test my homemade ungrounded CHT probes, but at ambient temp, they all read correctly. I'll give them a boiling water = test at some point to see how that holds up at higher temps. =20 =20 Cheers, Rusty (progressing by deferring everything until later) ------=_NextPart_000_00DB_01C40C56.663AB220 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message
Tracy,
Thanks for the clarification.  I plan on making my = own CHT=20 thermocouples by tig welding one end of J-type thermocouple wire and = inserting=20 into a 1/8" hole in the rotor housing.  What method would you = suggest to=20 keep the sensing end from shorting once inserted into the rotor = housing? =20 Would 1/16" shrink tubing work?

Mark S.  
 
I talked to=20 Tracy about this today, mostly because I made all those J-type = thermocouples by just connecting the ends of the wire, but = realized=20 that they aren't grounded, and I didn't ground them inside the = connector=20 either.  Tracy suggested grounding them at the junction = instead. =20 My reply was something like "I don't see how you could generate a = voltage when=20 you're grounding the connection of the two wires".  His reply was = to look=20 at a spark plug type CHT probe and notice that they're doing the = exact same=20 thing.  I sure can't explain it, but it must work. =20
 
I have yet to=20 thoroughly test my homemade ungrounded CHT probes, but at ambient temp, = they all=20 read correctly. I'll give them a boiling water test at some point to see = how=20 that holds up at higher temps. 
 
Cheers,
Rusty=20 (progressing by deferring everything until=20 later)
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