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Postby networkcrasher on Thu Jan 29, 2009 12:12 am

So I'm looking for a Type K thermocouple for over-the-lip measurements on my Fluke 287 with my thermocouple adapter. It accepts the blade style connector for a thermocouple.

Anyone have a good place to pick one up?
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Postby JimG on Thu Jan 29, 2009 12:38 am

networkcrasher wrote:So I'm looking for a Type K thermocouple for over-the-lip measurements on my Fluke 287 with my thermocouple adapter. It accepts the blade style connector for a thermocouple.

Anyone have a good place to pick one up?

Nice meter. Curious to hear how it works for this.

One option is to buy a spool of 30AWG type K thermocouple wire from http://www.omega.com for $21. Their part number is TT-K-30-25. You'll also need a mini-connector (Omega part number SMPW-K-M) or two. Pretty simple to make an over-the-lip probe by twisting a short length of stripped wires together to form a sensing tip.

Alternatively, I've been known to make up a probe or two with my t/c welder in exchange for a charitable contribution of your choosing :)

PM me if interested.

Jim
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Postby erics on Thu Jan 29, 2009 12:50 am

Well, I have been possibly underbid :)

At least I could possibly sell you the Type K connectors I never use.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com
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Postby networkcrasher on Thu Jan 29, 2009 10:38 am

JimG wrote:Nice meter. Curious to hear how it works for this.

One option is to buy a spool of 30AWG type K thermocouple wire from http://www.omega.com for $21. Their part number is TT-K-30-25. You'll also need a mini-connector (Omega part number SMPW-K-M) or two. Pretty simple to make an over-the-lip probe by twisting a short length of stripped wires together to form a sensing tip.

Alternatively, I've been known to make up a probe or two with my t/c welder in exchange for a charitable contribution of your choosing :)

PM me if interested.

Jim


Thanks! I was able to pick it up for a song, and my previous 89 was getting a bit long in the tooth. Still works just fine, but the 287 does logging, and I thought it would be a good opportunity to get a new meter, a logger, and a temp probe all in one. I'm hoping it works well for this, but if it doesn't, I still have a nice meter on my hands for all of my other projects.

As far as creating my own t/c, are there any parameters one needs to abide to as it relates to stripped wire length, twisting length, etc? I suppose I just didn't realize one could make their own t/c so easily - at least K types anyway.

Checked out a t/c welder on Omega. Pretty interesting. 1800 bucks though? Geeeez! That's a LOT of t/c's before an ROI!



erics wrote:Well, I have been possibly underbid :)

At least I could possibly sell you the Type K connectors I never use.

I'll be contacting you shortly, Eric. I figured you'd find your way into this thread, but didn't want to just ask you directly. :) I'm sure you have other things on your plate!
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Postby JimG on Thu Jan 29, 2009 2:06 pm

I have the 189 model, and I really love it. Too bad it has been discontinued. The 189 measures temperatures well, so I'm guessing your's will, too. For very critical measurements, I think a digital thermometer is always going to do a slightly better job because of cold junction issues.

Look for posts by Jim Schulman on building thermocouple sensors. As I recall, he advises to strip around 1/4", wrap the two wires tightly together, and then fold over the wrapped pair.

Omega is very proud of their t/c welders 8) A respectable DIY unit can be built, however, using a 24VDC PSU, a bank of BMF capacitors, a pure carbon rod, and some small pliers.

Jim
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Postby networkcrasher on Thu Jan 29, 2009 2:45 pm

JimG wrote:I have the 189 model, and I really love it. Too bad it has been discontinued. The 189 measures temperatures well, so I'm guessing your's will, too.


Err, thanks Jim. I think I mistyped and meant 87. I know it doesn't do temp, which was a good reason for me to go to the 287 for its temp and logging capabilities.

I'll check out Jim's posts. Thanks for the tips! Eric is going to help me out with some t/c's for my GS3, so I should be up and running later next week. I know the GS3 has been brow beaten quite a bit wrt temp, but I'd like to have a look see for myself.
-Mark
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Postby cafeIKE on Thu Jan 29, 2009 7:54 pm

If you are going to use an over the lip sensor, be sure you either don't have insulation inside the basket or that you have a drip cutout in the insulation before the meter connector. The drip cutout must be the lowest point in the wire. 10bar is ample pressure to force coffee down the wire inside the insulation. If the meter is vertical, coffee will run into your meter. :cry:
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Postby networkcrasher on Thu Jan 29, 2009 9:02 pm

Good tip Ian, thanks! I assume even the 30g wire has this issue?
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Postby cafeIKE on Thu Jan 29, 2009 9:11 pm

I don't know that all wire has this issue. I do know that some 24g K and 36g T do.
Wanna experiment on your meter? :wink:
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Postby networkcrasher on Thu Jan 29, 2009 9:12 pm

Haha, considering my meter, not so much. Considering my curiosity, maybe. :twisted:
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