Infrared thermometer

Weezbo

it behaves in very predictable ways.

believe it or not, that even though it doesn't sound coherent it is exactly as light behaves*~/:)

it is either coherent or it is incoherent :)

GoCat

Infrared Thermometer question

So, I picked up this cool Fluke 62 infrared thermometer on Craigslist a while back. I love it -- got the new radiant floor working, and I keep pointing the thing at the tile and wood floors. it's addictive!

I also use it near the boiler and manifolds. Interestingly, it doesn't seem to work AT ALL on copper pipe. I point it, up close, at pipe that's warm to the touch and it tells me 65F. (No way!) The brass manifold doesn't seem quite right, either.

Is there something about the metallic surface that screws this up? I thought all materials emit IR the same for a given temperature. What's going on here?

KindyMan

wrap the pipe in black electrical tape. it will give you the correct reading now...

[Deleted User]

Emmesivity....

Dull the pipes with anything (spray paint, pipe dope, electrical tape, duck tape) and it iwll read more accurately. The differential is relevent, but the surface temp is not.

Some manufacturers actualy provide an emmmissivity dulling crayon for use on shiny metallic surfaces.

Some shiny cast black iron elbows will read low as well.

ME

Brad White

Unless it is a steam pipe

then you get a correct reading and a funny smell if you forget to remove it.

I use a shot of flat black high temperature spray paint for the purpose, but even regular paint of almost any color will do.

You will notice that shiny copper at 180 degrees practically reads room temperature. As ME noted, the emissivity is the key. IR thermometers do not read temperature so much as they read and interpret emitted infra-red radiation and correspond it to an indexed temperature.

Reading certain specific electromagnetic bands is similar to how we know how warm the surfaces of distant stars and planets are.

Unfortunately and despite this technology, some of our physicians still insist on detailed in-situ readings.

GoCat

thanks, all..

The black spray paint occurred to me. Tape sounds easier. Will give it a try.