In a message dated 20/09/05, gmvoeth@........... writes:

> Can you tell me what the roll off rate is for the Piezo element... Is it 
> 40db per decade like I understand is true for magnet coil velocity systems ?

Hi Geoff,

       As far as I know, it is an ordinary acceleration response, which is 20 
dB / decade above the RC roll off, which is why I use such a high input 
impedance amplifier to give the maximum period.
       The magnet / coil velocity systems are 40 dB / decade, since you have 
the force / deflection of 20 dB / decade and the induced voltage / velocity 
giving another 20 dB / decade.  

       Regards,

       Chris Chapman
In a message=20=
dated 20/09/05, gmvoeth@........... writes:



Can you tell me what the ro=
ll off rate is for the Piezo element... Is it 40db per decade like I underst=
and is true for magnet coil velocity systems ?




Hi Geoff,



       As far as I know, it is an ordinary=
 acceleration response, which is 20 dB / decade above the RC roll off, which=
 is why I use such a high input impedance amplifier to give the maximum peri=
od.

       The magnet / coil velocity systems=20=
are 40 dB / decade, since you have the force / deflection of 20 dB / decade=20=
and the induced voltage / velocity giving another 20 dB / decade.  



       Regards,



       Chris Chapman