FLIR

Time to spin up the kooks again. Melt, kooks, melt.

BeeJ, in did thusly write:

If you're looking for a homebrew project, take a look at the FLIR in the Neato vacuum cleaner, there's been a lot of people taking that out of the vacuum and using it for other purposes.

FLIR imagers are really cool, but also expensive. If all you want to do is look for leaks, try one of these from Black and Decker: I have two of them (the 2nd one bought after I misplaced the first). Point the device at an inside wall to set a reference level. Then, run it along window frames, door joints, wall outlets, etc to check for temperature differences. It has a red/green/blue LED that lights up the test area, indicating whether the test area is hotter, same, or colder than the reference temperature.

Unfortunately, it's kinda useless for finding hot spots on PCB's. For that, I use various liquid crystal sheets. Just lay it over the PCB and watch the colors change: For identifying the exact component, I use a thermistor probe.

Do the math. I'm gonna use round numbers, YMMV. If you want to look at a PCB with SMT devices, you may want 1mm resolution. If your IR scanner has 160pixel resolution, that gives you a 16cm field of view. That's close focus and the depth of field will be lousy. Will be useless for scanning a wall for leaks.

More likely, affordable scanners will work fine for the wall leaks and be useless on small components.

Unless you get an IR scanner with zoom and/or macro focus adjustment... or have a close-up lens made out of Germanium, it'll be hard to make both measurements with one device.

People overestimate the temperature measurement capabilities of IR. Emissivity plays a big part when measuring random devices on a PCB. I did some experiments 30 years ago. Turns out that spraying a board with foot powder normalized the readings nicely. Problem was that the foot powder wouldn't wash off. Bummer...

Kapton tape is very good for emissivity. Really works well when placed on a gold plated part. It is very black to long wave IR.

Laying around I have some Neil Brown, USA sub-mm fast response thermistors. Next time I'm in that situation I will try one along with non-contact IR thermometer

On Wednesday, October 31, 2012 10:57:02 AM UTC-7, tm wrote:

On 10/30/2012 3:00 PM, BeeJ wrote: >> Looking at FLIR handhelds to do a bu nch of tasks including identifying >> hot components / traces. I also plan to use it for monitoring room air >> leaks and wall insulation. >> >> 1) ar e there any features of a particular FLIR model that is >> advantageous? >> >> 2) is there a place to get a better price break? New! One unit. >> >> > Do the math. > I'm gonna use round numbers, YMMV. > If you want to look at a PCB with SMT devices, you may want 1mm > resolution. > If your IR scanne r has 160pixel resolution, that gives you a 16cm > field of view. That's cl ose focus and the depth of field will be lousy. > Will be useless for scann ing a wall for leaks. > > More likely, affordable scanners will work fine f or the wall leaks > and be useless on small components. > > Unless you get an IR scanner with zoom and/or macro focus adjustment... > or have a close- up lens made out of Germanium, it'll be hard to > make both measurements wi th one device. > > People overestimate the temperature measurement capabili ties of IR. > Emissivity plays a big part when measuring random devices on a PCB. > I did some experiments 30 years ago. Turns out that spraying > a b oard with foot powder normalized the readings nicely. > Problem was that th e foot powder wouldn't wash off. Bummer... Kapton tape is very good for emi ssivity. Really works well when placed on a gold plated part. It is very bl ack to long wave IR.

Some 20 years ago we found that ordinary black electrical tape [non shiny] gave excellent correlation to measurement with a contact probe on 'bright' metal parts when 'looking' with Fluke IR probe. Cheap and easily removed af ter testing.

Neil S.

bunch of tasks including identifying>> hot components / traces. I also plan to use it for monitoring room air>> leaks and wall insulation.>> >> 1) are there any features of a particular FLIR model that is>> advantageous?>> >> 2) is there a place to get a better price break? New! One unit.>> >> > Do the math.> I'm gonna use round numbers, YMMV.> If you want to look at a PCB with SMT devices, you may want 1mm> resolution.> If your IR scanner has 160pixel resolution, that gives you a 16cm> field of view. That's close focus and the depth of field will be lousy.> Will be useless for scanning a wall for leaks.>

useless on small components.> > Unless you get an IR scanner with zoom and/or macro focus adjustment...> or have a close-up lens made out of Germanium, it'll be hard to> make both measurements with on e device.> > People overestimate the temperature measurement capabilities of IR.> Emissivity plays a big part when measuring random devices on a PCB.> I did some experiments 30 years ago. Turns out that spraying> a board with foot powder normalized the readings nicely.> Problem was that the foot powder wouldn't wash off. Bummer... Kapton tape is very good for emissivity. Really works well when placed on a gold plated part. It is very black to long wave IR.

gave excellent correlation to measurement with a contact probe on 'bright' metal parts when 'looking' with Fluke IR probe. Cheap and easily removed after testing.

Piece of cake; cut the tape into hundreds of tiny pieces and stick one on every SMT part on the board. Should work great.