Infrared heat guns

[Rodbuster]

Good morning,

I have several questions concerning these guns.

1) are they really needed?
2) how accurate are they?
3) brief description on how they work
4) do they give you the temp. of the tires outside casing or the temp. of the air inside?
5) would they give you the temp. of the bearing?

6) I've seen these from $19. to over $1000. what is a good one at a reasonable price?
7) What do you do if your 50 miles from nowhere and your tire is heating up?
8) How often do you suggest we check the tires? (I guess the answer would be...as often as you want or, as
as often as you stop)

Thank you very much for your answers.
Dick

 

[Hastey]

1) are they really needed? No but saves you from actually having to feel the hubs and tires. They are just handy.

2) how accurate are they? That just depends on the brand, quality, etc. I have a $30.00 Harbor Freight and it works fine.

3) brief description on how they work. Magic! However thermal tech works.

4) do they give you the temp. of the tires outside casing or the temp. of the air inside? It is all outside temp. You'll figure out what normal is and go from there.

5) would they give you the temp. of the bearing? No, the hub temp.

6) I've seen these from $19. to over $1000. what is a good one at a reasonable price? Refer to question #2 but I am considering the DeWalt 18v that Lowes has.

7) What do you do if your 50 miles from nowhere and your tire is heating up? Try to figure out what is causing it and then figure out if I'm going to fix it or cripple it to somewhere. I carry enough tools with me to do most any repair I need. To include spare bearings.

8) How often do you suggest we check the tires? (I guess the answer would be...as often as you want or, as
as often as you stop) I constantly do visual checks at every stop and check tire pressure often as well. I should be checking daily but I don't.

 

[Rickhansen]

Good Morning Dick,
I've used IR thermometers for years in the HVAC business, and because I use it at home, I can offer my opinions. First, your not in NASCAR, so your not looking for the same detail they are. A few degrees difference in temperature across the tread, or from tire to tire is perfectly normal.

To answer your questions:
1) No. I/R's are not really needed, but they are relatively cheap and knowledge is power. A good tire pressure gauge is sufficient normally. Set your pressures cold and check daily while traveling.
2) Accuracy is dependent what you but you buy, of course. The one I own is about 1%. That sounds pretty good, but the range of the device is roughly 500 degrees, so 1% gives about a 5 degree accuracy, not so good in the big picture. I think you are more concerned with repeatability though, because your looking for the change in temperature across the tire, from tire to tire, or over time during operation.
3) I/R's are simply a non-contact thermometer. They have a laser for aiming, and have conical focus area that they measure temperature through infrared detection. The farther away from the surface, the larger the focal spot gets and your measurement becomes more of an average over that area.
4) The I/R will give you the surface temp only. What would the temperature of the air tell you anyway?
5) The I/R will give you the temperature of the SURFACE of what you shoot. The bearing is inside a cup, covered in grease, etc. If you shoot your wheels near their centers after driving for an hour, and find one wheel is 100 degrees higher than the other 3 wheels, you should be very suspicious of that wheel.
6) For normal use around the house and RV, I wouldn't get too carried away. I'd be leery of the $19 device, $50 to $100 seems reasonable. Consider specs, but again don't get to hung up on accuracy. If your device is off by 2 degrees, it will generally still be off by 2 degrees an hour down the road too. Reflectivity of the surface, like a shiny wheel, will throw the I/R off a bunch so you might have to take several readings and approximate them anyway.
7) 50 miles from nowhere and your tire is heating up? Let it cool down, check the tire pressures, slow down, get to a service center and have it checked.
8) How often do you suggest we check the tires? (I guess the answer would be...as often as you want or, as often as you stop) Exactly. Very hot conditions, rougher roads, loaded heavier, and higher speeds all cause increased tire heat. I'd check more often under tougher conditions.

The long and short, if you got a hundred bucks to spend, an I/R and a GOOD pressure gauge are both good tools. A good pressure gauge probably being the more critical of the two. The I/R will certainly come in handy for many other applications (Oven, A/C, furnace, refrigerator, etc.) and provides you with more info to make good decisions so can be a good investment too.

Hope this helps.

 

[JohnDar]

I've got one of the HF $50 I/R guns. I use it on the truck since I don't have TPMS on it. Info, that's all, unless there is a serious mismatch between the tires. For the trailer, I've got the TST system. Even there, until you've run it a bit, the initial temp and pressure increases may give you angst until you figure out what's "normal." You may find the recommended alarm set points are not valid for your rig.

 

[TXBobcat]

I have Pressure Pro and an IR gun from Radio Shack. I check my tires if my tire pressure starts to rise a lot..

What do you consider a high temperature for your tires? I mainly look for a large difference between tires. If they all are running about the same temperature and one is quite a bit more then I start looking for a problem.

BC

 

[santafesoul]

Accuracy is dependent on the unit AND proper use. http://www.allqa.com/IR.htm How they work is also explained at this site.

 

[tireman9]

When measuring a conductive uniform surface like a metal wheel or hub you will get a reasonable reading. If you do not measure the flat surface of a tire where the lug or element of the tire is not identical in size you will get a much larger variation. Tires have many different size and shape parts of the tread. The bottom of a groove can be 100F hotter than the surface so how will you "average" your reading" The hottest part in inside the structure but you are measuring the surface. Rubber is a poor conductor of heat so again is not uniform.