Infrared Thermometer

[alexanderkidd]

Was wondering if it's OK to measure melted lead temperatures with an infrared surface thermometer. Have a Lyman Big Dipper and I'm not sure it's getting as hot as it used to, my infrared reads from 380-500 on the surface. Not sure if that's directly comparable to what you would get with a dipper-style lead thermometer (since I don't have one to compare).

[NSB]

I once worked for one of the biggest radiator manufacturing plants in the world and my job was quality engineer for the molten solder pots used to make the radiator tubes for copper/brass radiators. I've tried using infrared thermometers on solder pots and never got the same readings the internal thermometers got. I think it was the flux on top giving the lower reading. I had good luck using the infrared on complete units coming out of the bake ovens and using it on other objects in the process. It just didn't work as well on molten lead. We used solder pots that held over 3,000 lbs of solder.

[dragon813gt]

No: http://castboolits.gunloads.com/show...ermometer-Test

[bangerjim]

No......No....and.......NO! Forget it.

IR thermometers work on the "black body radiation" principal (remember HS physics class?) and will not read shiny surfaces correctly.

This has been cussed and discussed at least a dozen time in the past 6 months.

So forget your cheapo IR thingamagig from HF for lead and molds. Use it to check your house register temps and things like that (not shiny).

banger-j

[Dale in Louisiana]

Get yourself a good-sized plain iron washer and float it on top of your lead. It won't take long before it's dark. You can even help it along with some cold blue (or HOT blue, if you want). floating there on top of the lead, it will be the same temperature as the lead, and when you shoot it with your IR thermometer, you should have a fairly accurate idea of temperature.

We used to do a few tricks like this when measuring IR signatures over a period of time.

dale in Louisiana
(Doing IR thermography since 1989)