Suggested Temperature Gun - Page 1
Forum section: electronics / general

author: EPAIII
author_rank: Super Contributor
timestamp: October 17, 2023, 05:52:42 am
content: I need a way of measuring the temperature of a number of things, not all electronic. There seems to be quite a number of them with a very wide range of prices. I recently purchased a solder pot that does not indicate the temperature of the solder. Checking it would be one use. But I want something that can be used for as wide a range of situations as possible.Any suggestions about features and brands would be appreciated. I do not have any price/budget in mind yet.

author: xrunner
author_rank: Super Contributor
timestamp: October 17, 2023, 11:33:46 am
content: You said "Suggested Temperature Gun" - not sure what you mean by that. Do you mean you want an IR thermometer, which has a simple digital readout? Or do you mean an IR camera, which is more capable and displays a wider area with colors to show the temps of all the items in the field of view? Pic shows both of them on my bench.

author: mendip_discovery
author_rank: Super Contributor
timestamp: October 17, 2023, 11:58:23 am
content: If I had the money I would go IR Camera, you can see the temperature clearer.You could still buy a K-type thermometer display and then use the array of probes you can buy for them.

author: wraper
author_rank: Unknown
timestamp: October 19, 2023, 12:59:29 pm
content: Quote from: EPAIII on October 17, 2023, 05:52:42 amWould be pretty much useless for this purpose. It's much more complicated than pointing it at just anything and getting correct measurement. If you have the money, get a thermal camera. With it it's at least much easier to figure out you're measuring not what you want.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 19, 2023, 02:37:14 pm
content: If you really want to know the temperature, use a thermocouple probe. The various temperature guns depend on assumption of emissivity of the surface you are measuring. This can be quite accurate, or wildly wrong for a variety of reasons, many not obvious at first glance. With that as a background, I find that the cheap guns ($20-$40) work well enough to not be the dominant error source. As with any temperature measurement system you will need to take the time to characterize it. Figure out how large the measuring spot is and how accurate the red laser indicating spot is, and get a sense of how reflections, surface roughness and surface coatings can change temperature indications.

author: PwrElectronics
author_rank: Regular Contributor
timestamp: October 19, 2023, 03:09:13 pm
content: Solder pot molten surface is probably too shiny to get a accurate measurement with IR I think. Same reason solder joints or large patches of tinned traces on the PCB will show up as cold with IR camera views. When doing board verification where temperature rise of the board itself is a concern and I need accurate results, the board surface gets a thin coat of flat (no glossy surface) paint from a rattle can. I used to use black but someone suggested white is better for this purpose.

author: PlainName
author_rank: Super Contributor
timestamp: October 20, 2023, 08:00:13 pm
content: I've had aTesto 825-T4for, well, seemingly forever. Great thing, but not available any more. Closest I could find is the826-T4which differs in the probe end. The USP of these is that you get both an IR spot (with laser targeting) at one end and a contact probe at the other. Lasts well and worth the price IMO (obvs!).Testohave quite a range of thermal measuring kit. They are relatively expensive and, uh, 'arty' in design but well made.

author: TimFox
author_rank: Super Contributor
timestamp: October 20, 2023, 09:40:29 pm
content: Typical kitchen-type digital meat thermometers, which use a thermocouple inside a stainless-steel probe housing, go up to 300oC for < $20.00 US.What temperature range do you need? SN63 eutectic solder melts at 183oC.

author: EPAIII
author_rank: Super Contributor
timestamp: October 21, 2023, 04:40:28 am
content: Thanks Tim, I may just try that for the present. The solder will not stick to stainless steel. And that may have enough range for the present.Having never used any of those IR meters, I guess I was hoping for something of a miracle. I should have known better. But one never knows, so I asked.I may get both the meat thermometer and and IR gun. But I am going to look at IR cameras first.Quote from: TimFox on October 20, 2023, 09:40:29 pm

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 21, 2023, 09:47:57 am
content: IR cameras are lots of fun, and really good for surveying large areas for unexpected temperature excursions, but are no better than a heat gun for measuring a small number of locations. Well they do also offer better spatial resolution (smaller measurement spot size) but the difference is small at the low end of the cost regime.

author: wraper
author_rank: Unknown
timestamp: October 21, 2023, 10:56:54 am
content: Quote from: CatalinaWOW on October 21, 2023, 09:47:57 amThe problem with IR thermometer is that you never really know at what exactly it points at and how wide area it measures. Laser pointer is useful only on large distance (with wide spot size) due to offset. Reflections are not obvious either.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 21, 2023, 02:18:11 pm
content: Quote from: wraper on October 21, 2023, 10:56:54 amThese are exactly the issues I suggested need to be worked out upon purchase of such a gun. They don't change over time as a rule so once you know your device you can use it effectively.Reflections are an issue, but can be anticipated and their effects minimized. And reflections are an issue for cameras also, albeit they are easier to recognize. But neither instrument can make a good measurement of a reflective surface.

author: wraper
author_rank: Unknown
timestamp: October 21, 2023, 04:01:27 pm
content: Quote from: CatalinaWOW on October 21, 2023, 02:18:11 pmWith camera you sort of can. If reflective surface it much hotter than surroundings so reflections are not significant, you can adjust emissivity coefficient and get reasonable reading. For example useful when you want to know temperature gradient over some flat thing. You can measure temperature at one point for example with thermocouple or put a piece of tape with good emissivity. When actual temperature is known at one point, you can adjust emissivity coefficient and get satisfactory reading over all area.

author: jonpaul
author_rank: Super Contributor
timestamp: October 23, 2023, 06:43:54 am
content: EPAIII1/ Solder pots need a thermocouple to check the melt. We use Omega or Fluke Type K in Teflon or Kynar, with appropriate meters for Type K.2/ Temo IR guns can give rough indications of temp but as noted emmisivity of the DUT affects read. Solder pots typically will NOT be accuratedadjusted by any IR gun or cam.3/ IR Cam is good to find a hotspot or insulation leak in a wall.They are either very costly or very inaccurate. Cheap IR cams WILL NOT solve any of your measurements.Jon

author: VK3DRB
author_rank: Super Contributor
timestamp: October 23, 2023, 08:22:00 am
content: Get aVevor SC240M.I bought one. It is excellent quality great performing thermal imaging IR camera for a relatively low price. Don't let the fact it is made in China put you off. This camera works a treat for electronics (including tiny SMD parts) or anything. Make sure it is the 'M' model and not the 'N' model.Very happy with this thermal imaging camera.

author: PlainName
author_rank: Super Contributor
timestamp: October 23, 2023, 08:31:50 am
content: Instead of Shouting Like No-One Can Read why not just post a link to the thing instead?Inportant aspect: can you fix the temperature scale or does it auto-change to match whatever you're looking at?