Re: Measuring SMT device temps with Infrared thermometers



On Mon, 27 Mar 2006 08:03:40 -0800, John Larkin
<jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> Gave us:

On Mon, 27 Mar 2006 09:25:13 GMT, Roy L. Fuchs
<roylfuchs@xxxxxxxxxxxxxxxxxxxx> wrote:

On Mon, 27 Mar 2006 01:10:21 GMT, "Bob"
<nimby1_NEEDSPAM@xxxxxxxxxxxxx> Gave us:


"EE_user" <EE_user@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:44272d89$0$15851$892e7fe2@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Anyone have any experience with using handheld Infrared thermometers
to measure small SMT devices? I see some devices for $30 and up.

It is possible to adjust for the emissivity differences between
different materials?

What about the ability to focus on a specific device? Like a SOT23?

We have a very expensive infrared camera which is often used to
determine temperatures across an entire circuit board. This is ideal
but inconvenient.

Thanks,


A SOT23 is going to be tough, with the IR units I've seen. The spot size is
a function of how far unit is away. You'd have to be pretty damn close to be
sure you're only picking up the SOT23.

Some have close focus capacity, but not the ones in Mouser or at
Fry's


The more expensive ones have a setting for emissivity, or you can just
calculate what the true reading is (if you know the emissivity of the part
under test).

True.

Or, you can just paint it black (for emissivity=1).

Not true at all. First off it would have to be a matte black, not
glossy, and it will only attain about a .98 emissivity, at best.
Then, there are the conductivity issues which may be a problem when
"painting" a SOT23 package. Most matte black paints have a carbon
based pigmentation.

These guys are the best.

http://www.mikroninfrared.com/Default.htm

Those look nice. Any idea of the price range?


The M-90s are likely a couple grand each.

The MI-N15s are likely half that or less.

The thermal imaging products are much higher.

I don't know exactly. I think they either have a price schedule on
the site, or will send you one, however.
.



Relevant Pages

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  • Re: Measuring SMT device temps with Infrared thermometers
    ... A SOT23 is going to be tough, with the IR units I've seen. ... The more expensive ones have a setting for emissivity, ... First off it would have to be a matte black, ... Any idea of the price range? ...
    (sci.electronics.design)
  • Re: Measuring SMT device temps with Infrared thermometers
    ... A SOT23 is going to be tough, with the IR units I've seen. ... The more expensive ones have a setting for emissivity, ... calculate what the true reading is (if you know the emissivity of the part ... First off it would have to be a matte black, ...
    (sci.electronics.design)
  • Re: Measuring SMT device temps with Infrared thermometers
    ... A SOT23 is going to be tough, with the IR units I've seen. ... The more expensive ones have a setting for emissivity, ... calculate what the true reading is (if you know the emissivity of the part ... First off it would have to be a matte black, ...
    (sci.electronics.design)
  • Re: Measuring SMT device temps with Infrared thermometers
    ... A SOT23 is going to be tough, with the IR units I've seen. ... The more expensive ones have a setting for emissivity, ... First off it would have to be a matte black, ... Also, painting it will change the way it operates, and alter the data ...
    (sci.electronics.design)