## PSN-L Email List Message

**
Subject: Re: Damping Test Device**

From: Bob McClure bobmcclure90@.........

Date: Fri, 17 Feb 2012 12:13:11 -0500

Hi Geoffry,
I wrote the page
http://www.jclahr.com/science/math/calculators/scientific_calculator.htmlusing
a formula supplied by the late (and revered) John Lahr.
It features a calculator which can compute sensor damping or Q based on the
amplitude of successive peaks in the sensor impulse response. Use "STO1"
and "STO2" keys to enter your input numbers. Both numbers should be
positive, even though the actual values have opposite sign. Be careful not
to let any amplifier bias affect your measurement of amplitudes.
When 1.0 is entered into register 1 at the bottom, and 0.1 into register
2, the resulting damping is 0.5911550337988976 and the corresponding Q
is 0.8458018140975397.
I test my sensors in a similar manner. I charge a 0.03 mf capacitor to 5
volts and discharge it across the amplifier input terminals.
Bob
On Thu, Feb 16, 2012 at 9:13 PM, Geoffrey wrote:
> Can someone here point me to a formula which converts
> the 1:10 ratio to a damping number relating to 1.0
> which is the calculated CDR of 1179 Ohms for this
> HS10-1 geophone ?
>
Hi Geoffry,

=C2=A0 I wrote the page=C2=
=A0http://www.jclahr.com/science/math/calculators/scientific_cal=
culator.html using a formula supplied by the late (and revered) John La=
hr.

=

It features a calculator=
which can compute sensor damping or Q based on the amplitude of successive=
peaks in the sensor impulse response. Use "STO1" and "STO2&=
quot; keys to enter your input numbers. Both numbers should be positive, ev=
en though the actual values have opposite sign. Be careful not to let any a=
mplifier bias affect your measurement of amplitudes.

=C2=A0 When 1.0 is entered=
into register 1 at the bottom, and 0.1 into register 2, the resulting damp=
ing is=C2=A0
0.5911550337=
988976=C2=A0and the corresponding Q is=C2=A00.8458018140975397.

=C2=A0 I test my sensors in a simil=
ar manner. I charge a 0.03 mf capacitor to 5 volts and discharge it across =
the amplifier input terminals.

Bob

On Thu, Feb 16, 2012 at 9:13 PM, Geoffrey

<gmvoeth@.........> wrote:<=
br>

Can someone here point me to=
a formula which converts

the 1:10 ratio to a damping number relating to 1.0

which is the calculated CDR of 1179 Ohms for this

HS10-1 geophone ?

[ Top ]
[ Back ]
[ Home Page ]