Infrared Thermometer with Class II Laser Targeting: Distance to Spot 8 to 1

[John Boy]

I bought one. Why? Because my gas mileage dropped down 5mpg and I wanted to determine if the calipers are locking on the rotors
* Put batteries in it and like a kid with a new toy ... pointed at the outside wall in the basement = 58 degrees! Had better insulate the walls!
* Hey, pretty neat. Opened the doors on the safes = 56 degrees.:groner:
Ideal storage of firearms should be 70 degrees and 55% humidity
Then the gray matter came alive ... I can use it to determine the temperature of my mold blocks before I begin to cast. Compare the reading on the mold to the pot temperature. If equal ... first bullet drops should be filled out and looking good. Won't replace my bi-metal in the pot but am sure it will have other uses. Like A/C temperatures at the grates in the vehicles and house

127405Temperature Range: -36F to 968F ... accuracy: (+or-) 2% above 32F and (+or-) 4.5% below 31F

[Mike W1]

Don't get your hopes too high on measuring mould temperatures. Lot's of talk on here about laser thermometers and I do have one. Clipped the following off somewhere or another, maybe on here. It'll give you an idea about accuracy.

"Before I retired from Zeiss, at least 2-3 times a year I had to engineer systems that would measure the exact temperature of machined parts prior to measuring their dimensions. (Engine blocks, heads, etc. in Big 3 auto plants.) So
I've done more than my share of study of temperature measurement methods. Let me say categorically that these
non-contact "laser" measurement systems are almost worthless. They measure infrared radiation from the target, and
that radiation varies wildly with what is called the "emissivity" of the surface. The industrial suppliers of these things claimed that they could tell me a temperature within 2-3 percent of displayed value, IF we sent a large number of samples
to them so they could measure the emissivity and calibrate their sensors. Any time a sensor required replacement, they had to go through the whole rigamarole again. Any time the surface finish changed, ditto.

Without calibration, and given unknown surfaces, they wouldn't guarantee accuracy to better than 25% of the displayed value! And that's industrial grade equipment costing thousands of $$. Bottom line, if you calibrate a Harbor Freight instrument against an accurate contact thermometer, you may be with 5% for the exact object you calibrated for. Any other object, you can be wildly off.

BTW the laser has nothing to do with the measurement process. It's just an aiming aid.

Best method is a low-mass thermocouple or RTD device, (thermistor). These are not expensive. Some under-$100 Volt-Ohm-Meters come with a thermocouple probe. I have had two of these, and they worked pretty well. I've never stuck one into melted lead, but there are versions that are encapsulated in ceramic which I would."

[dragon813gt]

I ran a simple test w/ a cheap handheld IR thermometer and a FLIR camera. Both failed miserably: www.castboolits.gunloads.com/showthread.php?190209-Infrared-Thermometer-Test

[bangerjim]

IR works of the "black body radiation" principal. Shiny silver surfaces will NOT work well at all. Liquid lead, aluminum molds.........no go for me.........and most others.

If you want to read Al molds, get some Birchwoo-Casey Aluminum Black at your LGS and make a good black spot on the side/end of the mold and shoot at that. It is NOT a paint, but a chemical blacken agent that works great of molds and certain Al alloys. Must be grease free. I use a Qtip to rub and apply it.

bangerjim

[ph4570]

Ditto on IR accuracy comments with regard to shiny objects.

Also, your mold temp should not be anywhere near the lead temp.

[dikman]

Thanks Mike, a very interesting article. It all seems like a lot of unnecessary hassle, just to possibly avoid having to return the first couple of cast boolits back to the pot.

[1johnlb]

Well if nuttin else you check the wife and see what kind of mood she's in while coming up the drive, or or play with your kitty and run him around in circles and make the wife laugh:drinks: there's always a good reason for getting new toys. But seriously my works great for getting the cat out the tree or making the neighbors nervous.

[Side by Side]

These don't appear to be very accurate, especially with reflective surfaces

[theperfessor]

The best use for these things is what the OP is already using them for. The worst use is trying to measure metal temperatures, shiny or otherwise. The best you can get is a comparative reading - i.e. when it reads 300 and the bullets cast well then you can use that as a figure you can return to the next time you use that mold. But it probably won't actually be 300, and there is no guarantee that somebody with a similar tool would get the same reading. Any recommendation of what temperature you suggest to somebody else based on your readings is not very accurate, unlike burying a thermometer or thermocouple directly in the mold block or the molten alloy.