PSN-L Email List Message
Subject: Re: Signal To Noise Ratio of a Seismic Sensor
From: Dave Nelson davenn@...............
Date: Sun, 26 Mar 2006 15:03:46 +1000
yup Chris
jst some more typo's :)
cheers
Dave
At 06:45 PM 25/03/2006 -0500, you wrote:
>In a message dated 25/03/2006, davenn@............... writes:
> Bi-FET Op-Amps .... eg the OPA 027 and similar
>series, rather 741 etc type
>Hi Dave,
> Google can't find an OPA027 ! and neither can I !!
> OPA27 are very low noise, but they are not Bi-FET The later types are
> OPA227 LT1007 etc
> In general, FET opamps have a much higher voltage noise than ordinary
> transistor types. I would not use one by choice in a geophone or a coil
> sensor circuit. Some of the less expensive / older types suffer from step
> noise - transient level or pulsed shifts.
>
> When you connect up a geophone, you need to wire the metal case to
> the earth / shield line.
>
> Regards,
>
> Chris Chapman
>
>
>No virus found in this incoming message.
>Checked by AVG Anti-Virus.
>Version: 7.1.385 / Virus Database: 268.3.1/292 - Release Date: 24/03/2006
yup Chris
jst some more typo's :)
cheers
Dave
At 06:45 PM 25/03/2006 -0500, you wrote:
In a
message dated 25/03/2006, davenn@............... writes:
- Bi-FET Op-Amps .... eg
the OPA 027 and similar
- series, rather 741 etc type
Hi Dave,
Google can't find an OPA027 ! and neither can I
!!
OPA27 are very low noise, but they are not Bi-FET The
later types are OPA227 LT1007 etc
In general, FET opamps have a much higher voltage
noise than ordinary transistor types. I would not use one by choice in a
geophone or a coil sensor circuit. Some of the less expensive / older
types suffer from step noise - transient level or pulsed shifts.
When you connect up a geophone, you need to wire the
metal case to the earth / shield line.
Regards,
Chris Chapman
No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.1.385 / Virus Database: 268.3.1/292 - Release Date:
24/03/2006
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.1.385 / Virus Database: 268.3.1/292 - Release Date: 24/03/2006
[ Top ]
[ Back ]
[ Home Page ]