Re: Accelerometers for >1000g measurements

On Thu, 5 Sep 2024 12:09:36 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2024-09-05 11:10, Glen Walpert wrote:

On Thu, 05 Sep 2024 07:07:25 -0700, john larkin wrote:
 

On Thu, 05 Sep 2024 06:22:04 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
>

On a sunny day (Wed, 04 Sep 2024 19:57:04 -0700) it happened john larkin
<jlarkin_highland_tech> wrote in
<md7idj1plqodnthuqpcemaphbrtotlqveh@4ax.com>:
>

On Wed, 4 Sep 2024 18:30:46 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>

So for this customer gig I need to measure the actual acceleration of
a parallel-rod transmission line that's being pounded into the ground
with a built-in slide hammer.  (It's for measuring soil moisture and
salinity by TDR.)
>
We're thinking about putting the TDR pulser and sampler in the part
that gets pounded (in a potted module obviously), so knowing how bad
the acceleration gets is going to be important.  I expect that it'll
be several hundred g in volcanic soil, so a full-scale range of
1000-2000 g would be about right.
>
None of the MEMS IC accelerometers go anywhere near that high.
Measurement Specialties makes them, but they're $160 in onesies, e.g.

>
>
If you can make it emit some ultrasonic sound you can measure the
received frequency shift from far away?
Same for RF likely...
?

>
No, just measure the voltage or the charge that it generates under
acceleration. It's a polarized, piezoelectric ceramic thing for 30
cents.
>
https://www.mouser.com/c/?q=ceramic%20resonator
>
One might also measure its resonant frequency vs acceleration.
>
I wonder how one would test it. At 2000 g's.

 
Compare to a single expensive calibrated accelerometer?  Not familiar with
Measurement Specialties, other possibilities are:
 
https://www.kistler.com/INT/en/c/accelerometers/CG21-accelerometers
https://buy.endevco.com/accelerometer
 

Thanks, Glen, good leads.
>
The PCB Piezotronics folks (formerly Endevco) have the single-axis,
+-50k gees model 350D2 for $1200ish in onesies, which we may wind up buying.
>
Cheers
>
Phil

Do you only need one. or do you want to put one into every probe?

If it's one, buy something expensive and calibrated.