Non contact infrared thermometer at Harbor Freight

[Ohio Rusty]

There is a hand held Non contact infared thermometer with laser targeting at harbor freight (or harbor fright depending ....) this week for $25.00. The pic shows a temp in the window on the thermometer gun of 950 degrees. I was curious to know if something like this might be good for measuring the temp of lead in the lead pot ?? Anyoen used one for this type of purpose ??
Ohio Rusty ><>

[dragon813gt]

Won't work. Lead is a shiny reflective surface. You'd have to match the emissivity of the lead which that cheap one won't do.

[HATCH]

No problem. Float a price of brass on the top of your melt for a few mins then shoot the brass.

[dragon813gt]

It won't work on brass either. I use one at work for shooting ceiling diffusers in offices to see if the air is warm/cold. They aren't meant for precise measurement. If I want to shoot water pipes I have to put a piece of black tape on the pipe. It doesn't work on dull finish brass ball valves. Also they take the temp over a wider area the further you pull the thermometer away from the object you're testing. A proper casting thermometer is the same price as the HF infrared. I can also tell you the cheap infrareds are just that, cheap.

[462]

Twenty bucks will get you a proper casting (Tru-Temp) thermometer.

[GT27]

I bought 1 a year ago,it works when you float a all copper penny,checked it with a casting thermo for accuracy and it passed with flying colors ! GT27

[375RUGER]

I bought one of those just a few weeks ago, because it was on sale, to measure some component temps of equipment at work. I took it home and measured something in the living room, the heat of my wood stove, then back to the other object, then the wood stove again. I found it to be inconsistent/inaccurate. After measureing the stove then back to the other object it would read that the original object was quite a bit higher than the original reading.
I took it back and when I really need one will get a higher quailty unit.
I've used quality digital units before and it did not matter if you measured extreme heat and extreme cold, back to back, it would read that same original temp each time.

[HATCH]

I don't use a cheap one. I have a Fluke model that works just fine.

[farmerjim]

Mine does not work on lead.
I will try the penny trick next time I cast.

[EDG]

Mine works fine I just aim it at the junction of the lead and the pot.
If there is a lot of dross on the melt it will work pointed directly at it. It also works well pointed at a sprue plate to measure the mold temperature.

[mold maker]

I bought one several years ago to set up a hot water heat system. It was inconsistent and inaccurate. Lots of stuff at HF is usefull in smelting/casting, but their digital infred thermometer isn't one of them.

[John Boy]

I was curious to know if something like this might be good for measuring the temp of lead in the lead pot ?? Yes, if one wants to measure the surface temperature exposed to the air with the fan whirling instead of the temperature down in the pot ... where one should know the temp and digging the dipper into

[1616s16]

will what have we found here, cheap is really cheap or it may do some of use????????????
1616

[EDG]

The digital infrared works fine. Check the pot with a thermocouple and meter at the same time for a while if you have any doubts. You can also point it into a dipper that has been submerged. Just hold the dipper under the surface and then let it float to the top and take a reading on the dipper. It is not rocket science. Like any thing that a bunch of people don't like they will find a way to make it not work if they try hard enough. If you want it to work you can find a way to use it. You may have to take 40 or 50 readings learning how to use it but it does work. You may have to put your thinking cap on.

[uscra112]

This keeps coming up. IR temperature measurement readings depend very heavily on a parameter of surfaces known to radiation engineers as emissivity. When I was evaluating this technique for an automotive manufacturing application (before I retired) I had to learn a lot about it, and the short answer is that it's pretty much useless for our purposes, if measurement of absolute temperature is wanted. Emissivity will affect the readings up to 20% or so of displayed value. (!!!) If you stick to measuring just one object, and the surface conditions don't change, you can get a relative measure that's good to maybe 5% of displayed value from day to day. That's the straight scoop from the people who engineer these things in the real world. Been there, done that, didn't bother collecting the t-shirt.

BTW the laser has nothing whatsoever to do with the measurement - it's just an aiming device.

[mold maker]

The digital infrared works fine. Check the pot with a thermocouple and meter at the same time for a while if you have any doubts. You can also point it into a dipper that has been submerged. Just hold the dipper under the surface and then let it float to the top and take a reading on the dipper. It is not rocket science. Like any thing that a bunch of people don't like they will find a way to make it not work if they try hard enough. If you want it to work you can find a way to use it. You may have to take 40 or 50 readings learning how to use it but it does work. You may have to put your thinking cap on.

That must be why I spent the bucks to buy the thing. Guess I just had money I wanted to spend.

[40Super]

I used a pricey one borrowed from a buddy a while back(I think it was a Mack Tools? had three dots in a triangle), It worked sometimes but wasn't reliable enough that I didn't bother to buy one. I didn't float anything though and it did work good on most "normal" stuff I played with.

[HDS]

Does anyone know if there exists a kind of quick read contact thermometer instead? Like something with a flat surface for a sensor, that would be suitable for pressing against hot things for an instant temperature snapshot. Like say molds.

[Case Stuffer]

I have a Raytek IR temp. gun and it works great but then it cost a bit more than $25 or even $50. I have used it on my molds when casting just out of curiousity but I have spent hundreds of hours perhaps thousands casting by sight and feel so I really do not case what the temps. are as long as the pot and molds get er done.

I know the trend is computerized controls with extremly accurate and closely controled temperature but as I am not a machine I can not maintain a constant rythm and so there goes all that hi tec accuaracyout the window unless one wants to monitor mold temp. also. Wonder how a Master Caster machine managed to crank out 2,400 lead pills per hour 40 years ago without a computer interface?

[LUBEDUDE]

Works great!

Just like anything else, you have to learn how to use it differently in different applications.

[EDG]

>>>Wonder how a Master Caster machine managed to crank out 2,400 lead pills per hour 40 years ago without a computer interface? <<<
Did you ever wonder why there is so much variation in the weight of cast bullets and that they do not shoot like the jacketed versions? With enough process control it would not be such an artsy fartsy process.

[Taylor]

I have one,bought it for my jeep.Not really sure if it is accurate at all.She reads 195-200 all the while the jeep is boiling away.

[HDS]

I think one of these would be perfectly suited to reading mold temperature, not enough range for the lead pot but inside what a mold ought to be:
http://www.triosmartcal.com.au/temperature/2192-extech-392052-flat-surface-stem-dial-thermometer.html

The best way to control the pot is just getting a PID temp controller, so I'm only really after a way to read my molds.

[uscra112]

Does anyone know if there exists a kind of quick read contact thermometer instead? Like something with a flat surface for a sensor, that would be suitable for pressing against hot things for an instant temperature snapshot. Like say molds.

We did have such a device which I used daily when I was with Zeiss. It was a thermocouple in a little ceramic pellet, tied to a computer. The trick for a quick read was that you held the thing on the surface for about five seconds, while the computer software took several hundred readings per second. It then extrapolated the rate-of-change to decide what the actual temperature of the object was. Worked fantastically well, accurate to within 1% of the displayed reading, which was hyper-critical to us.

You know what uses the same technology? Those "swipe the forehead" fever thermometers you buy at the drugstore. Doubt they'll work for lead, though. . . .