Re: Extech EX410A DVM Don't Buy

On Thu, 17 Oct 2024 17:23:46 -0700, john larkin wrote:

On Sun, 6 Oct 2024 01:43:44 +0200, Klaus Vestergaard Kragelund
<klauskvik@hotmail.com> wrote:
 

On 06-10-2024 00:15, Jeff Liebermann wrote:

On Sat, 05 Oct 2024 07:52:25 -0700, john larkin <JL@gct.com> wrote:
 

On Fri, 04 Oct 2024 16:07:24 -0700, Jeff Liebermann
<jeffl@cruzio.com>
wrote:
>

On Thu, 03 Oct 2024 14:46:46 -0700, john larkin
<jl@glen--canyon.com>
wrote:
>

Extech EX410A  DVM  Don't Buy
>
The auto power off is incredibly stupid. I'm going to throw mine
away and get something usable.

>
What don't you like about the auto power off feature in the EX410A?

 

It shuts off in the middle of a measurement, and you have to rotate
the very klunky range knob all the way back to OFF and then all the
way back to where it was.
>
It's OK for one-time measurements I guess, but terrible for bench
experiments.

 
I agree.  That's a serious problem.
 
Some of the Extech meters have a way to disable auto power off.  It's
usually disarmed by holding down one of the buttons while turning on
the meter.  I couldn't find anything like that for the EX410A.  I'll
look again when I'm more awake.
 
However, my Uni-T UT-210E does have a way to disable auto power off.
 From the user docs at:
<https://meters.uni-trend.com/download/ut210e-user-manual/?

wpdmdl=7228>

 
- Automatic power-off: when measuring, if the rotary button has not
pulled out in 15 minutes, the instrument will automatically power off
to save energy. In automatic power-off mode, turn rotary button to OFF
and restart the machine, or click any key to wake the instrument.
 
- Turn off automatic power-off function: press and hold SELECT key,
then power-on start, you will heard 5 buzzing which means automatic
power-off function is cancelled. Turn off and restart the machine,
automatic power-off function will be recovered.
 
- The buzzer will send out 5 warnings 1 minute before automatic power
off. A long buzz will be heard before power off When automatic power
off function is canceled, you will hear 5 continuous warnings in every
15 minutes.
 
I just tested it and found that it works as described.  Maybe a meter
made by Uni-T might be less stupid.  The manual doesn't mention that
every time you turn the meter off, auto power off is re-enabled.  You
need to remember to hold down the SELECT button every time you turn it
on.  For bench use, I don't see this as much of a problem.  For my
use, which involves turning it on/off many times, it's still a
problem.
 
I mentioned that the UT-210E is hackable.  See:
<https://github.com/bdlow/UT210E?tab=readme-ov-file#modify-the-auto-

off-and-backlight-times>

The programming looks easy, but providing the adapter needed to
program the DM24C02A EEPROM seems rather messy.  For an 8 pin SOIC
package, I would desolder the device and do the editing in an external
programmer.  Whether this is worthy of the time and effort involved is
your decision.
 

Extech was planning to introduce some thermal imagers, so FLIR bought
them to stop it. That's all FLIR really cares about.

 
I didn't know that.  FLIR bought Extech in Oct, 2007.  After 17 years
and once FLIR owns the IP (intellectual property), I would have
expected FLIR to sell off Extech in parts and pieces:
<https://www.flir.com/about/about-flir/about-extech/>
"In 2007, Extech was acquired by Teledyne FLIR, a global leader in
innovative infrared thermal imaging solutions."
Well maybe.  FLIR did sell off Extech Data System, which made portable
printers in 2009.  Looks to me that FLIR had too much cash on hand and
needed to buy something quickly:
"FLIR Systems Reports Record Fourth Quarter and Full Year 2007
Financial Results"
<https://www.globenewswire.com/en/news-release/2008/02/07/1049954/0/

en/FLIR-Systems-Reports-Record-Fourth-Quarter-and-Full-Year-2007-
Financial-Results.html>

"Cash provided by operations during the quarter was a record $55
million. Cash used during the quarter included $40 million for the
acquisition of Extech Instruments..."
$50 million cash for Extech seems to me to have been a bargain
purchase.
 

For IR measurements for handheld, I use Seek Thermal:
>
https://www.amazon.com/gp/product/B07GX8XTG5/ref=ox_sc_act_title_1?

smid=ATVPDKIKX0DER&psc=1

>
And for table top:
>
https://www.dyt-ir.com/dytspectrumowl-ca-60-rd-grade-thermal-analyzer-

with-macro-lens-product/

>
>
>

What does that cost?  I got a similar Flir unit (a freebie!) but it's
mostly useless. The post on the stand limits how big a board you can
image, and it doesn't have an adjustable focus.
 
The Uni-T 260B handheld thermal imager, with the close-up lens, is
great.

*Very* useful indeed for troubleshooting boards where something's gone
short or low-z.

I got their 139C dvm too, and it's fine. It reads about 0.2% low. When
it times out, push some button and it wakes up.

They do make accurate meters. I've had one for about 7 years now and it's
a main go-to for everything except very high voltages or energy levels.

I blew the current fuse on the Extech, couldn't figure out how to
replace it, so I threw it away.

That was the right thing to do, John.