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Rex Johnson

Fluke Pyrometer question - need correct Thermocouple!

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Per advise here I bought a Fluke T1/T2 pyrometer similar to this pic.

s-l640.jpg

I tried it out on my bisque and found that the thermocouple I have with the Fluke type connector did not read accurately.

It would read like 72 degrees when the temperature was actually 200 degrees...

If I used the pen probe type and  it read correct.

digi-sense-0851665-type-k-std-pen-probe-

There must be something I do not know about the specs. I've never had one of these, only the standard digital or traditional kiln set up.

Obviously the pen probe isn't going to hold up to a glaze firing.

I also have two K-type insulated probes that I believe came with the Fluke but they have only one wire...

digi-sense-0850586-type-k-kapton-insulat

I don't know enough about what kiln type thermocouple that will work with this Fluke.

Any ideas on what type thermocouple I need and where to find one?

 

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I have a TPI 343 (K Type, which Aardvark lists as a "Skutt Dual Input Digital Pyrometer" - their image clearly depicts TPI 343 - with one K Type probe, $130, today Aardvark lists at $155), which defaults to F but can be toggled to C ...

...which is 'bout all I have to offer right now; 71.4C ~= 160.5F, any chance the problem is units?

My probe has two wires.

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Use fluke meters a lot they are older but no matter-you forget about the supplied thermocouple (pen plug)

 

and get a plug with two wires that fits your meter which you wire up to a standard thermocouple in a ceramic sleeve

the plug that comes with the meter is just for low temp stuff.

if you undo the two screws in that plug in photo you will see there are two wires.

often you can find them on e-bay-you need the plug and the 5-6 foot two wire-many times its fuzed at end and you can cut that off and wire to a thermocouple.

with my broken arm one hand typing is hard

 

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See that's what's weird. I have the thermocouple that came with my cheap digital pyrometer from China, has the ceramic cover and two wires, regular kiln pyro with the digital plug.

It doesn't read the heat...

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The thermocouples that come with the pyrometers are junk.  If you search amazon for "High Temperature k-type Thermocouple Sensor Ceramic Kiln Furnace with connector plate 2372F 1300C CR-02" that's what I use, I only fire to cone 6 so it's plenty for me.  You can spend a lot of money on a fancier one, but no matter how accurate they are they can't measure heatwork so keepin an eye on them cones is the important thing.  

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2 minutes ago, liambesaw said:

The thermocouples that come with the pyrometers are junk.  If you search amazon for "High Temperature k-type Thermocouple Sensor Ceramic Kiln Furnace with connector plate 2372F 1300C CR-02" that's what I use, I only fire to cone 6 so it's plenty for me.  You can spend a lot of money on a fancier one, but no matter how accurate they are they can't measure heatwork so keepin an eye on them cones is the important thing.  

Do you use a Fluke digital pyrometer or something else?

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Good. On the same page.

I'm sure it can be calibrated but I don't know how (yet).

It worked fine with the pen probe but of course the probe started to get, uh, over heated...

I guess I could just try one of these...or maybe just by the thermocouple as you mentioned.

High Temperature k-Type Thermocouple Sensor Ceramic Kiln Furnace with Connector Plate and Hook up Cable 2372F 1300C CR-07

91PWE1-O0pL._SL1500_.jpg

81wyMJIjLGL._SL1500_.jpg

Edited by Rex Johnson

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4 minutes ago, Rex Johnson said:

Good. On the same page.

I'm sure it can be calibrated but I don't know how (yet).

It worked fine with the pen probe but of course the probe started to get, uh, over heated...

I guess I could just try one of these...or maybe just by the thermocouple as you mentioned.

High Temperature k-Type Thermocouple Sensor Ceramic Kiln Furnace with Connector Plate and Hook up Cable 2372F 1300C CR-07

91PWE1-O0pL._SL1500_.jpg

81wyMJIjLGL._SL1500_.jpg

I bought this one, it was about half the price: High Temperature k-type Thermocouple Sensor Ceramic Kiln Furnace with connector plate 2372F 1300C CR-02 https://www.amazon.com/dp/B01N0YA9ZR/ref=cm_sw_r_cp_apa_GT6SBb3PHP235

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If you just need a wire it's nothing special.  It wouldn't register anything without two wires connecting though since it measures resistance between two different metals that change with heat. There should be two wires, one on each screw on the back of your thermocouple. Might be worth looking up how to calibrate your meter if it can be.

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the one above from amazon hooked to a standard pyrometer will work fine-just pug it into a fluke-remember k thermocouples at high temps are off some anyways they are just a guide.

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17 hours ago, liambesaw said:

If you just need a wire it's nothing special.  It wouldn't register anything without two wires connecting though since it measures resistance between two different metals that change with heat. There should be two wires, one on each screw on the back of your thermocouple. Might be worth looking up how to calibrate your meter if it can be.

It measures the voltage output not the resistance of the wire. I think with the wire connecting to the thermocouple you don't want to use certain types of metals because they can interfere with the reading as adding another type of metal can create its own voltage.

thermocouple-types.png

@Rex Johnson If you could measure accurately what mV are output by the thermocouple you could work out if it's the thermocouple or the meter.  Are you sure the meter hasn't selected the wrong type of thermocouple because mine has an option to select which type you have.  My guess is the very thin wire is two wires, did you open the connector to see if there's two?

The voltage is also non-linear so I think cheaper meters don't take that into account so can give you wrong readings. I remember in writing my kiln software I had to add an equation to 'straighten' the line.

Edited by High Bridge Pottery

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The best online source for information on thermocouples that I have found is OMEGA Web Technical Reference https://www.omega.com/techref/   
scroll down to the Temperature Related section and pick and choose the topic of interest. 

To see the variety of thermocouple stuff available go to: https://www.omega.com/temperature/ 

LT 

 

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5 hours ago, High Bridge Pottery said:

It measures the voltage output not the resistance of the wire. I think with the wire connecting to the thermocouple you don't want to use certain types of metals because they can interfere with the reading as adding another type of metal can create its own voltage.

thermocouple-types.png

@Rex Johnson If you could measure accurately what mV are output by the thermocouple you could work out if it's the thermocouple or the meter.  Are you sure the meter hasn't selected the wrong type of thermocouple because mine has an option to select which type you have.  My guess is the very thin wire is two wires, did you open the connector to see if there's two?

The voltage is also non-linear so I think cheaper meters don't take that into account so can give you wrong readings. I remember in writing my kiln software I had to add an equation to 'straighten' the line.

I'll check those wires today.

Point is that the new to me Fluke would not read more than room temperature no matter the setting using the thermocouple/wire/plug, until I just used the pen probe and then read the temp fine.

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8 minutes ago, Rex Johnson said:

I'll check those wires today.

Point is that the new to me Fluke would not read more than room temperature no matter the setting using the thermocouple/wire/plug, until I just used the pen probe and then read the temp fine.

Is your meter set to type K?  Mine defaulted to N which gave a bad reading with my K thermocouple.

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17 hours ago, Rex Johnson said:

I'll check those wires today.

Point is that the new to me Fluke would not read more than room temperature no matter the setting using the thermocouple/wire/plug, until I just used the pen probe and then read the temp fine.

Sounds like it is a dodgy thermocouple then if the Fluke is reading fine with the other probe.

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Liam, Yes set to K and tried both T1 and T2/C and F.

HBP,  methinking the same. It's just so strange it worked last season, and now it don't...

I'll fiddle about today during a bisque with what I have, new parts coming in by tomorrow for a glaze hopefully.

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40 minutes ago, Rex Johnson said:

Liam, Yes set to K and tried both T1 and T2/C and F.

HBP,  methinking the same. It's just so strange it worked last season, and now it don't...

I'll fiddle about today during a bisque with what I have, new parts coming in by tomorrow for a glaze hopefully.

need a new battery?

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