Infrared thermometer for spot checking fin tube runs

swvawethead

For spot checking temp at last section of convectors before returning to the boiler, and this could also be for other sections, a spot of flat matt black paint on the copper pipe for aiming the target light on infrared thermometer.
Does this sound ok?

JDHW

Just wrap a bit of black insulating tape around the pipe and use that.

coldguy23

I like the southwire 31212S dual laser thermometer because not only does it have two lasers (which helps to pinpoint the bounds of the reading area) but it has adjustable emissivity. It sounds like you already know what that is since you mention using matte black paint- but yes, I would agree that is a good idea. There is a paint out now that is especially designed to have an emissivity of like 99.99 or something crazy high; I forget who makes it... But for practical purposes standard high-temp paint should be fine and give accurate results with most IR thermometers.

For those who are unfamiliar with emissivity- You can lookup an emissivity table to see how drastic the emissivity coefficient can vary depending on the material. A perfect blackbody object has a theoretical emissivity coefficient of 1.0, meaning it emits 100% of the heat energy it absorbs, whereas some shiny metals can have an emissivity of 0.1, meaning it emits only 10%. Thus if you try to read a shiny tin surface it may show only a fraction of the temperature it actually is. Most IR thermometers have a fixed emissivity setting of around 0.95-0.98, which is good for most surfaces, but highly inaccurate for the aforementioned shiny metal surfaces. For example I built a powdercoating oven out of an old-fashioned metal trashcan and it read around 40 degrees with a 350F fire blazing inside when I used a fixed emissivity IR.

swvawethead

Thank you for replying - after I posted this and going to sleep!

Emissivity definitely was a consideration but stumbled upon these in 2017 and stuck them on the supply and return pipes above the boiler. They do give a quick glance check on anything goofy happening but by no means are considered spot on.
Did first get a simple infrared gun in 2016 then learned about emissivity for the first time - in the included instructions.

Will keep it simple and go the paint/IR gun route.
It's only for spot checking and there are many convectors in the house in three zones I've been rambling on about in another thread with much help from members.
There is a spray can of flat black mentioned in an older thread and will post a pic of that when checking on the system next door.

swvawethead

Silly surface temp sensors - supply side one needs to be better adhered.
Pressed on the pipe insulation and it read higher. Was reading lower than the return.
Will leave them on for now and start masking and spraying target spots of this stuff.
Not going to mess with tapped in temp gauges which are awfully tempting but life gets in the way.
Recommended by a member back in 2016/2017.


Thanks for reading and commenting.