On Thu, 31 Oct 2019 13:47:36 -0400, Jim Horton
wrote:

On 10/31/19 11:59 AM, Jeff Liebermann wrote:


About half of my various digital multimeters can be used as a
thermometer using a Type-K thermocouple probe. Perhaps it's time to
junk your 10 year old meter and just use a multimeter? Or, perhaps
add some additional functionality, such as a data logger?

I can't deduce what style of Type-K probe you managed to destroy. So,
pick a photo that looks familiar as any Type-K probe will work.
https://www.google.com/search?q=k-type+thermocouple+probes&tbm=isch
https://www.ebay.com/sch/i.html?_nkw=type-K+thermocouple+probe


I still have the actual K probe:

https://imgur.com/a/4H9rNrs

The probe, when plugged in, still shows temperatures but very
inaccurately.

The insulation appears to be shredded near the thermocouple. As
others have suggested, cut it back to where the insulation is still
intact, and weld the tip. That's weld, NOT braze, solder, glue,
crimp, sleeve, or twist. Just weld.

You can see what happened in the third image with parts
of the feed wire having insulation burned away.

I only see one image and one URL, but it's enough. The insulation is
gone. I'm not sure why you're getting "very inaccurate" readings. Are
the readings high, low, erratic, intermittent, or insane?

Perhaps it could be repaired?

Yes, by welding. However, it would be prodent to spend a few dollars
and buy a new Type-K probe so that you can compare your repaired probe
with one that is more likely to be accurate.

Never thought I could, just assumed I ruined it.

Nope. Note my domain name: LearnByDestroying.com. That means you
don't really understand how something works until after you've broken
it and subsequently repaired it.

The insulation looks like some form of Teflon or similar.

The high temperature insulation can be PTFE (Teflon), PFA
(perfluoroalkoxy or Neoflon), XC, XS, XR, or XC4:
https://www.omega.com/en-us/wire-and-cable/thermocouple-and-rtd-wire-and-cable/xc-xs-xt-xl-wire/p/XC-J-20-50
https://assets.omega.com/pdf/cable-and-wire/thermocouple-and-rtd-wire-and-cable/XC_XS_XT_XL_WIRE.pdf
Chemically resistant wire uses FEP (fluorinated ethylene propylene)
insulation.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558