Tune able reference vibrator for 500 g

[joniengr]

I have developed electronics for accelerometers which are rated up to 500 g. The sensitivity of the accelerometers are 10 mV /g. In the electronics I get 4 V to 5 V signal when I shake the accelerometers manually, which correspond to 400 g and 500 g. To be sure I need to put the accelerometers on tune able reference vibrator which I can tune in steps of 10 g up to 500 g. Any idea how to find and where to get such reference vibrator if they exist.

 

[dick_freebird]

MIL specs for "shock and vibe" will use such a
thing, but I do not know its proper name. The
g forces will definitely be calibrated, the military
loves them some chain-of-calibration docs
when they come to buy off the lot at source
inspection.

Third party hermetic-capable assembly & test
houses would probably have one or more, and
maybe their customer-facing Web presence
has "tool porn" pics of their equipment set.

However as far as I've seen in the semiconductor
assembly & test niche, these are -just- shakers,
no interest or ability for electrical test meanwhile.

Board / box level companies in the MIL hardware
business may be required to show -operation-
while shaking. That's a layer or two up from where
I sit.

If you wanted constant acceleration, that might
be easier - centrifuge, like. Put the thing on a
spinning platter at known RPM and distance from
the spindle? But getting the data out, could still
be a problem.

Maybe something simple and stupid like take
the head off a junk compressor piston and strap
the sample down? That would be a sinusoidal
oscillation, I imagine somebody who remembered
their undergrad physics (or was willing to crack a
book) could probably calculate the g force at
peak acceleration from RPM and stroke-length.
I bet automotive performance folks, like ones
who sell fancy connecting rods and crankshafts,
might have either web pages discussing or even
calculators for piston force on connecting rods
(might need to back out the mass to get the
acceleration, if that's put plain).

Maybe one of these works for you?

 

[BradtheRad]

Countless sci-fi films feature a space station shaped like a donut. It rotates about the axis to generate gravity (which is a kind of acceleration). Increase speed of rotation to increase the acceleration. I'm not sure if accelerometers generate a signal this way but it sounds like a stable and inexpensive method.

I don't know how many rotations per second creates 1g. I suspect whatever it is, you have to go 500 x as fast to create 500 g.

Your sensor needs to send its signal via radio, or possibly through rings which maintain continuous contact.

If you truly wish to shake the sensor, there's the motorized device which I've seen dentists use to mix the silver-mercury amalgam for my fillings.

 

[BradtheRad]

To continue the thought experiment...
Convert rotary to linear motion using a contraption such as below. (Images grabbed from internet). At rest your accelerometer sends 1 g by definition.

As the motion speeds up, there is a point where it sends zero G on the way down, and 2 g on the way up (I think). It occurs at only one speed but I think it ought to provide a scale which you can calibrate to.
This is not the same as generating gravity by rotation but it's a method that can be done without having to entangle the sensor's leads.

 

[joniengr]

It is possible to made something with the combination of signal generator and speakers such that the speaker diaphragm vibrate with the known acceleration proportional to the signal frequency and amplitude set in the signal generator.

This can be an accelerating device source to test the accelerometer sensor along with the electronics which I actually need to test.