Does anyone have any rough figures for the mounted resonant frequencies for accelerometers?

I realise that these are going to be pretty variable depending on the size of the sensor, surface they are mounted on, design of mount etc. etc. etc. but a ballpark figure would be helpful.

I'm particularly interested in Magnetic mounts, but spikes, studs, quickfit bases would all be useful to me and others no doubt.

Cheers.

Most specs I've seen range from 15 - 30K Hz. It should tell you in the data sheet. If you have the part# someone here will probably have the information.

One thing to keep in mind would be the max frequency response you will get from the different mounting techniques. It is quite possible that you would never even see the resonant freq of your sensor.

Attached is a graph of the max frequencies based on mounting technique.

If you have a specific sensor you should be able to go to the manufacturer's website to determine the resonant frequency.

Regards,
Marty Wilkins

sensor_mounting_techniques.doc (103 Kb, 32 downloads)

Well thanks guys. I phoned the manufacturer, and they told me 10kHz, (it's a Monitran 1100 for your info) but I didn't think about the different types of magnet, like your excellent diagram demonstrated, Waylon. I use a curved surface magnet, which suggests about 2kHz (I know these are all going to be pretty rough figures, but 8kHz is a lot)

I'll have to ring them and check again.

Found a spec Sheet you might be interested in.

According to the Spec Sheet the mounted Resonance is 18KHz. However, as discussed mounting different methods can really change things.

http://www.monitran.co.uk/attachments/products/790/MTN1100DS001703.pdf

Keep in mind when using a magnetic mount, the mounting surface is critical. On a machined flat smooth surface, I believe the response is better than generally believed. But mount the same sensor and magnet on a rough or paint covered surface and the natural frequency will drop considerably.

If you are using magnetic mounts, I highly recommend installation of target diska. Proper installation requires scrapping paint down to bare metal and the thinnest possible layer of a rigid adhesive. The result will be extremely repeatable measurements taken at the same location no matter who makes the measurements.

Jon
www.spintelligentlabs.com