molten metal temp

[Tom O]

I’ve never seen the stainless being used like that the DIY ones I’ve seen use the graphite rods that are drilled out for the thermocoupler

 

[jcdammeyer]

I’ve never seen the stainless being used like that the DIY ones I’ve seen use the graphite rods that are drilled out for the thermocoupler

It's been working well for 20 years. Yikes... 20 years...

 

[Tom O]

It's been working well for 20 years. Yikes... 20 years...

And that’s why I don’t like hindsight

 

[Johnwa]

Curious if you've tried it and possibly compared the readings with an immersion type? Everything I've read thus far indicates IR guns will not give you the temperature of the melt...an actual comparison and knowing would beat guessing. I use one of these with off the shelf K probes for aluminum.

Edit: Thanks for sharing that chart John. A handy little thing to have nearby.

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As far as I’ve been able to find out the non contact pyrometers won’t work with aluminum. They depend on much IR is emitted but molten aluminum IR emission is remarkably low.

 

[ChazzC]

As far as I’ve been able to find out the non contact pyrometers won’t work with aluminum. They depend on much IR is emitted but molten aluminum IR emission is remarkably low.

I found several free references (including Omega https://assets.omega.com/pdf/tables_and_graphs/emissivity-table.pdf) which list Aluminum at 1,100F as having an emissivity of 0.19; the ThermoWorks IR-IND has a range of of 0.10 - 1.0 so should be able to get a good reading. However, none of the free references list molten Aluminum, and I don’t have the capability of getting any where near even 1,100F.

 

[Johnwa]

I found several free references (including Omega https://assets.omega.com/pdf/tables_and_graphs/emissivity-table.pdf) which list Aluminum at 1,100F as having an emissivity of 0.19; the ThermoWorks IR-IND has a range of of 0.10 - 1.0 so should be able to get a good reading. However, none of the free references list molten Aluminum, and I don’t have the capability of getting any where near even 1,100F.

I did find similar numbers ranging from about 0.04 to 0.19 depending upon the alloy. These were all for solidified aluminum.
This morning I did find this. https://www.williamsonir.com/aluminum/

 

[historicalarms]

Just noodling here as a non- high heat castor ( my casting limits out at arounf 750) but wondering for those that need high temp pyrometers...Lots of big trucks at wreckers with turbo pyrometers and gauges that read as high as 1600 I seem to remember, will need a 12 volt power source but should be usable and cheap for a hobbyist

 

[ChazzC]

I did find similar numbers ranging from about 0.04 to 0.19 depending upon the alloy. These were all for solidified aluminum.
This morning I did find this. https://www.williamsonir.com/aluminum/

Interesting reading (and a PDF to add to the “Reference” folder): it appears like everything else, if you want a more accurate & reliable measurement you need to spend more (lots more) money.