Best way to check temperature?

[gopherslingshots]

I am using a little fire brick forge and would like to know what the best way is to check the temperature? Thermocouple, laser-thing, etc, what do you guys think? Is there an analog thermometer that goes that high?

 

[Atlas Knife Company]

I use a $3 thermocouple from eBay and a $9 digital multimeter. Most multimeters will read high enough, but are a couple degrees off over 1800° F. Make sure you get a thermocouple with at least 3' of metal wrapped cord. You'll have to cut and splice a little, but you should be able to make it work for a lot less than the expensive ones.

 

[grizzled gizzard]

Look for an Omega handheld digital K type thermocouple thermometer with an 18" probe.

They are surprisingly inexpensive ($150-$250) for an industrial tool that measures from -320 to 2500*F within 1* accuracy.

I use it to keep track of how slowly I'm cooling blades in a LN tank, and minutes later I'm checking forge temp.

Easily one of my most indispensable tools.

 

[Daniel Rohde]

I'll have to add this to my bag of tools!! thanks for the tips guys!

 

[Ken H>]

You might wish to read the specs on those SS type TC - usually it's 400ºC or less. Since this is for forge work you'll need something in the 2,000 ºF range. Take a look at this TC with ceramic covering:

http://www.auberins.com/index.php?main_page=product_info&cPath=20_3&products_id=39

You can read the output in mV on a DVM, OR, many DVMs have a degree scale that reads type K TC.

Auber also has a complete package here: http://www.auberins.com/index.php?main_page=product_info&cPath=17&products_id=199

You will need to select the sensor that has the ceramic covering, AND you might wish the 8 AWG TC rather than the 11 AWG TC if you plan LOTS of time in the forge.

Ken H>

 

[Stacy E. Apelt - Bladesmith]

For reading the air temp , a roast in the oven, or your hot tub, most any type TC will work.

For reading forge temps and knifemaking work, a robust type K TC is needed. You need an 8-10 gauge probe ( 1/8") with leads long enough to get away from the heat source. If permanently mounting in a forge, use a ceramic sheath.

The reader can be a multimeter, pyrometer, or a PID. The accuracy varies greatly, so look closely at the accuracy and range. Some say things like "+/- 3 degrees...or 3%". At 1500F, that is +/- 45 degrees. That is close enough for many things, but not really good for HT.

Take several readings and average them for the best results.

Use a TC block to connect the TC leads to the wires going to the reader, and observe polarity. You must use TC wire that matches the TC ( type K). Regular speaker or lamp wire is the wrong type, and will make the reading inaccurate. Best method is to use a TC plug and cord that fits the reader device, or install one and use it. The plugs are polarized, and the wires are correct.