Sixth Sense IR Thermometer LT300

[Battenkiller]

All the talk about IR themometers coupled with my discovery of the inherent inaccuracies in the bi-metallic magnetic units has led me to the decision that an IR thermometer is the best way to learn my new stove so I can maximize its heat output while minimizing the risk of damage.

I found this unit that seems to do everything mentioned without breaking the bank:

http://www.instrumart.com/Product.aspx?ProductID=18425

Sixth Sense isn't one of the main names, but I found a few scientific studies where it was use to collect temperature data, so it can't be all that bad. This model, the LT300, has the following desirable features:

- Temp range from -76ºF to 1400ºF (-60ºC to 760ºC)
- D:S ratio of 20:1 (with a minimum spot size of 1/2" @ 12")
- Adjustable emissivity (0.10 to 1.00)
- Accuracy of +/- 1% throughout the range, or 1ºC max
- Free hard case
- Free K-type bead probe
- Free shipping
- Lifetime product support
- $119 price tag

So, if anyone can see any reason why this won't do the trick, let me know. Otherwise, I'm going to pull the trigger on it (sorry... couldn't resist the pun) later today.

BK

 

[tutu_sue]

I've had that one for over a year. Works great.

 

[firefighterjake]

BK . . . I'm sure that model would work and work very well . . . but I would suggest saving your money. Buy a cheap, but very reliable IR thermometer from Harbor Freight . . . these things are not going to be used and abused so a cheap model like this should work fine . . . besides running a woodstove and relying on temps is more of a "using the temps as a guide" type of thing . . . absolute, calibrated numbers and temps are not needed.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96451

 

[begreen]

Mine is a basic automotive unit, ATD-701. They sell for $40-60 depending on where purchased. It covers -76F to +1022F.

 

[twitch]

I bought the one below from the Depot last year, 49.97 and it has worked well. It doesn't have the range like the one you mentioned, but I'm satisfied.

IR Thermometer

 

[k3c4forlife]

Cen-Tech Flexible Infrared Thermometer Model 94233.

It was $9.99 on Ebay. Great IR Thermometer.

 

[Battenkiller]

Just a follow up on the new IR thermometer....


Ordered it at noon on Thursday, arrived UPS Ground the next day at 10AM. I'm in a one-day delivery zone, but still, pretty darn fast service on the part of the seller if you ask me.

I got this one because it has other features I like for other purposes. For one, it reads to 1400ºF. I have a forge and do a few knives and other tools. Accurately checking for when I reach the critical temperature for quenching was always a lot of guesswork, and I never knew if I really got it right until I sharpened the tool and used it - way too late in the game. Now I can tell in an instant, while using it as a tool to teach my eye what the the proper colors are at each temperature.

It gives min and max alarms, temperature difference, average, etc, as well.

This model also has a receptacle for K-type thermocouples (a free low-temp probe came with it), which is a convenient way to measure the temperature of lots of things (like liquids, air, moving parts, ovens and BBQs, etc). Now when the wife asks what temperature the BBQ is, I can say, "248.6ºF and dropping at about 1.2º/minute" (while I dodge a deftly tossed pot lid).

I spent about an hour walking around the house, comparing the probe reading of the air temp with the non-contact IR readings of various surfaces. I discovered that the single pane glass in my basement windows was about 12º lower than the double pane glass in the new door, that black surfaces and white surfaces read basically the same, that the face cord of cherry I have stacked 36" from the side of my stove is 110ºF on the stove side and only 84º on the far side. Room temp on that side was only 76.6º, but on the stove side was pushing 100º. This morning, I discovered that the outside air temp was 18º, but the concrete walkway (in the shade) still measured a very cold 2ºF from last night's sub-zero temps.

Oh, and I also used it on my stove (who woulda thought of that?). I found that both of my magnetic thermometers were just about spot on (the old VC one reads about 15º higher than the new Rutland one, which gives almost identical readings as the IR does), but... there is a considerable lag time with the magnetic ones as the stove ramps up. I got a 650ºF griddle top reading on the Vigilant with the Rutland, but the IR showed me that it was 762º just 1/2" to the left of it. Within five minutes, they both read the same 750-ish. I also discovered that stove top temps are not a true indication of what's going on inside the box. There were definite hot spots. At start up, the top got hotter than the sides and front by about 200º, but as the stove settled in with the damper closed and secondary air added, top temp hovered around 650º while the front and sides reached above 800º in spots. And most of the inside of the firebox was pretty near the outside temps in each region of the stove, although most of the coal bed was bright orange (it topped out past 1400ºF and I couldn't get a reading).

In short, lots and lots of very interesting data that won't do me a damn bit of good in keeping the place toasty warm today when temps are frigid and the stove suddenly doesn't want to respond to my sweet caresses.

The same make (Sixth Sense) is available from "Instrumart" without all the bells and whistles. It is called the LT100, and is on sale right now for only $49 (free shipping and no tax in NYS). Seems like quality equipment, and it comes with free lifetime support from Instrumart (you actually get to talk to an engineer instead of some sales gal).

 

[obrien040362]

when you take a measurment do you shoot through the glass or open the doors and shoot at the fire?

 

[Battenkiller]

Well, I don't have glass in my doors, but if I did I would shoot the glass. I've been told that most stove glass (actually a ceramic material, not real glass) blocks IR radiation from passing through it. If you open the doors you will be getting the temp of the inside of the firebox. Inside there, the coals themselves can be as high as 1500ºF. I've maxed mine out at that point, they can get even hotter than that if you have a lot of primary air coming into the stove.

You want to know the temp of the glass itself, so the best thing to do is to shoot the outside of the glass from a slight angle, maybe 10-15º. That will avoid the problem of some stove glass that may not block all of the IR radiation and might pass some radiant heat from the flames. In general, I don't think it's much of a problem, but a physicist who sometimes posts here says it can be, so who am I to argue? Best to angle it slightly and avoid having your sensor "see" any flames.