|
|
|
Temperature Gun
- Thread starter Gpz900
- Start date
I often see people use the IR temp guns incorrectly. The following is a summary that might help.
There are various models of IR thermometers on the market, and many of them are fairly similar. When IR thermometers are pointed at their intended target, they tend to capture the infrared energy that is emitted from that object. Infrared energy can be transferred in three different ways: reflected, transmitted, and emitted energy.
Most IR thermometers are calibrated to measure emitted energy since that typically represents the truest temperature of the target object.
Essentially, IR thermometers can be accurate when they are used properly. However, the user should be aware of a few factors that can potentially affect the accuracy of IR thermometers.
The first factor is the distance that the unit is held from its target. When temp. guns are pointed at a target; they measure the temperature of the target in a circular spot. The farther the IR thermometer is held away from the target, the more area that will be included in the diameter of the temperature measurement.
So how can the user know the size of the area being measured by the IR unit, in relation to the distance the user is from the target? Raytek Corporation, an infrared temperature measurement instrument manufacturer, wrote a technical article that expresses the distance from the target in relation to the spot measurement is dependent on the actual IR thermometer’s built-in ratio. In other words, if you are using an IR gun that measures at a 4:1 ratio, and you are measuring 4 ft. away from the target, the spot measurement in this case would be approximately 1 ft. in diameter.
Let’s say you are using the 4:1 unit, and trying to measure the temperature of a tire when you are standing 6 feet away from the bike. In this case, the spot reading has exceeded the size of the tire, so you are potentially measuring not only the tire, but also whatever else is surrounding the tire in that area.
Additionally, with this extra space in-between the thermometer and the target object, you now have a bigger area of measurement where fog, smoke, vapors, or some other type of suspended matter could cause some interference resulting in a misrepresentative temperature reading. This suspended matter could absorb some of the emitted energy from the target, showing a lower temperature reading than the actual temperature of the target object.
Another factor that can affect the accuracy of the IR thermometer is the emissivity of the object being measured. Emissivity is measured by the ability of an object to emit energy by radiation. Emitted energy indicates the surface temperature of the object. The emissivity of an object is rated on a scale from 0 to 1. In general, the duller, or blacker a material is, the closer its emissivity value will be to 1. Most organic, painted, or oxidized surfaces have emissivity values close to 0.95. The more reflective or shiny an object may be, typically the closer their emissivity value will be to 0.
Therefore emissivity is less of a factor on tires however labels on new tires that haven't been removed would be a factor.
Last edited:
LOL at this review:
"I originally bought this on sale to check for drafts around our home, and while it works adequately for this purpose, it makes a way better cat toy!
Hold the trigger and aim the laser the floor, walls, even the ceiling and watch your cats run like mad!
Nevermind a dog whistle - we have a cat beeper! As soon as they hear the beep from this reader they all come running to play.
Oh, it's also handy for checking temperatures too ;-)"
"I originally bought this on sale to check for drafts around our home, and while it works adequately for this purpose, it makes a way better cat toy!
Hold the trigger and aim the laser the floor, walls, even the ceiling and watch your cats run like mad!
Nevermind a dog whistle - we have a cat beeper! As soon as they hear the beep from this reader they all come running to play.
Oh, it's also handy for checking temperatures too ;-)"
Also,if you are using it for tires, it will only measure surface temp. So measure your rim cold and ensure you see a rise in the rim temperature. Then you have heat penetrating thru the tire. Otherwise you can still get cold tearing.
Very handy to diag a dead/misfiring cylinder, Hit each exhaust pipe and look for a radical difference in temp. Thats what I use mine for the most.
If anyone missed the deal in Canadian Tire, here's your second chance: http://www.newegg.ca/Product/Product.aspx?Item=N82E16896268001
Yes and therefore the emissitivity factor comes into play due to the colour of the rim and the distance from the object that you are measuring becomes more critical.
Gpz900
Well-known member
Thanks for the tip about checking the rim, I would have just checked the surface. What kind of temperature difference am I looking for between a hot and cold rim? Is that even a valid question? Does it all depend on type of tire and psi or is there some sort of "standard"
Your rim will start out at ambient amd should get up to 35 ish. That's with our warmers. I can"t comment on other makes. In New Orleans with DiSalvo we were getting upwards of 50 C,, but I would say on an average day you should see 35+. If your rim temp does not go up the tire is not getting heated all the way through.
Well guys, I though the temperature gun I bought when I saw this thread would've had to wait a long winter until it's time for heating my slicks, but who would have known, it's put in use as of today. My daughter got a pet, and we're using the temp gun to take the temperature of the pet's home 
On behalf of the women in my family, thanks for sharing the deal!
On behalf of the women in my family, thanks for sharing the deal!
Too good for the hand burning method, eh?
|
|
|
|
|