IR Thermometers/ Pyrometers

Contemplating buying an IR thermometer for work, home and vehicle use.

I've used them at work for mostly steam piping systems/ traps and checking recip compressor valves but being lunch box size they always seemed to find a new home. They seemed inexact depending on the measuring distance, material and surface finish. There's a learning curve/ compensation for material/ finish but once known is better to have than not I thought. If I'm going to be hands on to clean/ prepare a surface to take uniform readings on several surfaces might as well go w/ contact readings.

My old digital contact pyrometer from the race car days was more consistent. Still required a clean uniform surface between different readings. Ideal for spotting a leaking compressor valve early on. The old pyrometer took a dump several years ago.

Also used magnetic base thermometers, simple stupid and $10-$50. Better suited for stationary equipment w/ flat surfaces but could adapt to pipe and such. Not much use on vehicles.

Anybody have input or recommendations on the latest IR thermometers or pyrometers? Gonna pick up some magnetic base units anyway.

I don't have any useful recommendations, but after my brother-in-law got his, he would use it to check the doneness level of steaks brought to the other diners from a few tables away.

I've got an HF one. I like it. Besides giving me things like the temp of the wort (beer making,) tires at the track, "that thing you just welded is still too hot to touch," HVAC output, wood stove, calibrate IAT and CLT for Megasquirt, the laser aiming part is great fun with the cats.

Hess, Do you find it accurate for wort? how about mash temps?

For tires at the track, you still want a "contact" pyrometer. Otherwise you won't get good data.

I don't do mash. I find it does just fine for wort. I have a candy thermometer and a special holder for it that I made from some 304 scrap so it will clip to the side of my Indian 2 gallon pot, but if I can't find the thermometer, I use my IR pyrometer. It is also easier to read.

A couple years back, I took my HF IR thermometer and my Longacre digital tire pyrometer to an autocross and used them back to back at the same time. The IR thermometer showed temps 5-7 deg cooler than the pyrometer (I guess this is because the pyrometer is measuring the temp under the surface of the tire), but (and this is the important part) it showed the same temp gradients across the tire.

Ex: across the tire the pyrometer would show 160 150 140, IR thermometer 153 143 133. These are not actual temps!

My take away: they can be a useful tool for amateur motorsports but in the event of more serious stuff maybe not.

I've used that same IR pyrometer for all kinds of stuff, one time was a weird misfire under load on a Spitfire motor. Could NOT pin down what cylinder and it would not do it at idle or free rev. Then I drove it till it did it, stopped the car and jumped out then used the IR pyrometer on the exhaust header tubes, discovered that the two front cylinders were running hotter than the rear indicating they were lean. Started pulling jets in the Weber sidedraft, sure enough the main emulsion tube for the front venturi had a little piece of white plastic stuck inside. Dug the bit of trash out, cleaned everything thoroughly, the misfire was gone and the exhaust tube temps were even across the board.

Curmudgeon wrote: A couple years back, I took my HF IR thermometer and my Longacre digital tire pyrometer to an autocross and used them back to back at the same time. The IR thermometer showed temps 5-7 deg cooler than the pyrometer (I guess this is because the pyrometer is measuring the temp under the surface of the tire), but (and this is the important part) it showed the same temp gradients across the tire. Ex: across the tire the pyrometer would show 160 150 140, IR thermometer 153 143 133. These are not actual temps! My take away: they can be a useful tool for amateur motorsports but in the event of more serious stuff maybe not.

So - it is a linear value with that of the pin type pyrometer? So... you can just add x number of degrees and get a reasonable, consistent value?

We have been doing enduros lately and being able to make a quick judgement during an early pit stop to schedule an early tire change or camber adjustment would be useful.

Thanks for the comparison, Curmudgeon. I just use my thermometer, also. It shows the differences across the tire and that's good enough for me.

I have a tire probe type that I used to use on the racecar. I then bought a HF IR and checked them against each other. The readings were largely identical-- perhaps a few a degrees lower on the IR. But I was mostly concerned with relative temps, so that wasn't a problem. I quit using the probe since the IR was instantaneous and easier to use.

Don't know if the steak comment is serious, but these things only have an effective range of maybe a couple of feet.

Giant Purple Snorklewacker wrote:

Curmudgeon wrote: A couple years back, I took my HF IR thermometer and my Longacre digital tire pyrometer to an autocross and used them back to back at the same time. The IR thermometer showed temps 5-7 deg cooler than the pyrometer (I guess this is because the pyrometer is measuring the temp under the surface of the tire), but (and this is the important part) it showed the same temp gradients across the tire. Ex: across the tire the pyrometer would show 160 150 140, IR thermometer 153 143 133. These are not actual temps! My take away: they can be a useful tool for amateur motorsports but in the event of more serious stuff maybe not.

So - it is a linear value with that of the pin type pyrometer? So... you can just add x number of degrees and get a reasonable, consistent value? We have been doing enduros lately and being able to make a quick judgement during an early pit stop to schedule an early tire change or camber adjustment would be useful.

Exactly. You need to remember that ambient temps are going to have a big effect on what the IR thermometer reads since it only reads the tread surface and the surface cools very quickly in colder temps, less so on a hot day. This means you won't have an accurate picture of the tire's true carcass temperature, that's where the contact pyrometer comes in. The IR thermometer will still show the gradient in each scenario, though.

You still have to do it like a contact pyrometer: hop out of the car and do it QUICK.

Curmudgeon wrote: You still have to do it like a contact pyrometer: hop out of the car and do it QUICK.

WE have a small crew so no jumping out but - the goal is to get a basic idea of what is going on without spending real time on it. Right now it's a visual for anything wrong in the time it takes to fuel. I'd love to be able to get a quick read inside-middle-outside of a tire or two that is relative other measures at the time it's taken for mental adjustments like:

• you are heating up the outside of the left front. back off until the driver change so we can put some camber in
• or... more likely - sweet jusus, stop berkeleying driving like a hack! You are roasting the rears. I'd like some tire left for my session :)

At harbor freight prices I'd be willing to duct tape three of them together to sweep the tire face in one shot.

Putting three together might speed things up and should be a decent early warning system. Give your crew guy an IR thermometer (or thermometers), a few of those tire temp sheets (download the pdf from Longacre) and go to town.

Giant Purple Snorklewacker wrote:

Curmudgeon wrote: You still have to do it like a contact pyrometer: hop out of the car and do it QUICK.

At harbor freight prices I'd be willing to duct tape three of them together to sweep the tire face in one shot.

That's borderline brilliant.

I just timed reading all four tires while saying out the temps for someone else to write down; under 35 seconds three different times. By myself, writing temps down, 60 seconds plus or minus a few seconds. You can shoot two tires from the front or rear(or sides)without moving and the notebook is on the ground once for each position. That's pretty quick.

I use a Fluke 63 at work in a refrigerated warehouse. It is pretty accurate, but not super precise. It is usually within a few degrees of a calibrated probe.

Where IR thermometers seem most useful is comparing temperatures. Where is it the warmest? How much warmer? I have a Ryobi IR thermometer at home. Last year, I had a grinding suddenly arise in my car. It was so loud, that I couldn't tell what corner it was coming from. When I nursed the car home, I used the thermometer to indicate where exactly the friction (ie heat) was coming from.

Well, finally bought an IR gun, the Fluke 62 Max Plus after a lotta foot dragging. Borrowed several IR guns from other shops at work from cheap base units up to the Fluke 63.

Fluke 62 Max+ has dual lasers to spot measured area and adjustable emissivity. Didn't shop around much after that vs the Fluke and didn't mind the $95 from Amazon. Oughta be fun and a work saver after getting acclimated to the new IR gun.