---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 08/07/22: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:54 AM - "Engine Monitors" article (user9253) 2. 11:56 AM - Re: "Engine Monitors" article (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 06:54:53 AM PST US Subject: AeroElectric-List: "Engine Monitors" article From: "user9253" The September 2022 issue of Kitplanes Magazine has an article titled, "Engine Monitors". On page 28 it says, "JPI uses "K" type or what is referred to as grounded probes. These are faster than "J" type or ungrounded probes." What does the type of metal have to do with whether or not the probe is grounded? Is the "speed" of a thermocouple a concern? There seems to be some misconceptions about grounding in the article also. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=507621#507621 ________________________________ Message 2 _____________________________________ Time: 11:56:28 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: "Engine Monitors" article At 08:54 AM 8/7/2022, you wrote: > >The September 2022 issue of Kitplanes Magazine has an article >titled, "Engine Monitors". >On page 28 it says, "JPI uses "K" type or what is referred to as >grounded probes. "K" and "grounded" are not synonymous. You can ground ANY type of thermocouple wire . . . of which there are perhaps a dozen. >These are faster than "J" type or ungrounded probes." Response time is related to how well the active junction of the thermocouple is thermally 'joined' with the medium for which you have a curiosity as to temperature. A grounded thermocouple is generally fabricated with the t/c junction crimped or welded to the inside of a metal tube which makes up the body of the probe. Ungrounded are a bit fussy to fabricate for responsive performance but not terribly so. See https://tinyurl.com/2h3a4ajf >What does the type of metal have to do with whether or not the >probe is grounded? not a thing >Is the "speed" of a thermocouple a concern? If one uses an EGT display to adjust mixture, then a more responsive display is helpful. But I can't imagine it being a show stopper should one find a really good deal on some insulated probes. The act of fine-tuning mixture is an en-route procedure where one is generally not in a hurry. In any case, the differences are on order of one or two seconds. Scroll down in the url cited above for an illustration of various t/c configurations. Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.