Land Jewell...not a shiny gem.

...or maybe it is.

I'll summarize with my e-mail I'd sent.



Hello,


The correct thermocouple extension wire for S6 was ordered this morning on #xxxxxxxxx,
Any extra can (and this type should) be used for S7 and S8.


If you enjoy details, read on;


I'd received a response from CM Furnace today, they recommended using "B" Thermocouple wire for our part number and temperature run. My original assumption was correct, but that was luck. I'd never heard of a "Land-Jewell" thermocouple before, nor had Paul, Pat, Scott, Dave... It doesn't show on any T/C charts or from Grainger, Newark, Omega.


I'd thought it was the manufacturer name. I Googled it and an engineering book came up, explaining the properties and applications of the "Land-Jewell". Paul had checked the platinum-rhodium ratio on the thermocouples he was working on, they didn't match any "letter" code for thermocouples, but they were the same in that engineering book I'd found (Pt60% Rd40%, and Pt80 Rd20%). The Land-Jewell T/C type is recommended for hi-temp and maintaining that temperature for extended periods, more durable than other ranges. "B" was the suitable extension wire CM Furnace said to use, which is Cu/Cu, the same as what the engineering book had recommended. So, Sinter 7 and 8 must be using this as well.


More info on the Land Jewell:


http://books.google.com/books?id=-375rPRjeGkC&pg=PA39&lpg=PA39&dq=land+jewell+thermocouple&source=bl&ots=9yZ8GtbkRG&sig=9jnr7523-eK0KgbClV_sXejG0Ek&hl=en&sa=X&ei=_1KET76FFIKa2gXj0KCdCQ&ved=0CJABEOgBMAU#v=onepage&q=land%20jewell%20thermocouple&f=false
Pages 39 to 45


The Land-Jewell is listed on the CM Furnace brochure, but no detailed explanation.


Regards,



I really hate mystery movies (they are always about some snooty know-it-all solving a crazy conspiracy-type murder), but this was a hell of a lot of fun...mainly because I'd learned something and shared the info with my peers. The job is getting done, and ahead of time (if we get the parts in soon). I guess this was more of a puzzle that nobody could help you with, you're pressed for time, and you start with a misconception of sorts.

Feels damned good to make progress.