In a message dated 11/02/2008 06:25:56 GMT Standard Time,  
photon1@........... writes:

Hello  John,
actually there are 2 units, the geophones are from Larry, L15 used  ones.
One will be on a hillside of conglomerate, 20mtr above  sea-level,  the other 
at sea-level on a sand flat.
Both have  houses nearby.



Hi Dale,
 
    Check the units for the correct damping resistors.  You need about 2.7 K 
Ohms total for a L15B, allowing for any parallel input  resistors on your 
amplifier board. I aways use metal film resistors.
    Seal both ends of the 6 core screened  connecting cable with silicone 
rubber to stop it 'breathing'.
    You will need to seal the top of the units and the  cable entry points, 
if you bury them. You can get an odour free silicone rubber  for this. DON'T 
use the sort which smells strongly of acetic acid - vinegar. You  may have to 
seal the cable entry on the opposite side if they are not in a  string. Don't 
leave any cropped wires exposed. Adhesive Heatshrink and be very  useful here 
and for joining cables..
    They should be set level using the spirit level  supplied and the arrow 
should point true North. 
    Alternatively, you could mount them in the bottom  of a vertical pipe, 
but this is more expensive.
    We can buy an adhesive mastic which never sets  called Blu-Tack / 
White-Tack, from stationers. It is used for attaching paper to  notice boards. It is 
very good for sealing a seismometer case.
 
    Regards,
 
    Chris Chapman



   






In a message dated 11/02/2008 06:25:56 GMT Standard Time,=20
photon1@........... writes:
<=
FONT=20
  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
=3D2>Hello=20
  John,
actually there are 2 units, the geophones are from Larry, L15 use=
d=20
  ones.
One will be on a hillside of conglomerate, 20mtr above=20
  sea-level,  the other 
at sea-level on a sand flat.
Both have=20
  houses nearby.


Hi Dale,
 
    Check the units for the correct damping resisto=
rs.=20
You need about 2.7 K Ohms total for a L15B, allowing for any parallel input=20
resistors on your amplifier board. I aways use metal film resistors.
    Seal both ends of the 6 core screened=20
connecting cable with silicone rubber to stop it 'breathing'.
    You will need to seal the top of the units and=20=
the=20
cable entry points, if you bury them. You can get an odour free silicone rub=
ber=20
for this. DON'T use the sort which smells strongly of acetic acid - vinegar.=
 You=20
may have to seal the cable entry on the opposite side if they are not in a=20
string. Don't leave any cropped wires exposed. Adhesive Heatshrink and be ve=
ry=20
useful here and for joining cables..
    They should be set level using the spirit level=
=20
supplied and the arrow should point true North. 
    Alternatively, you could mount them in the bott=
om=20
of a vertical pipe, but this is more expensive.
    We can buy an adhesive mastic which never sets=20
called Blu-Tack / White-Tack, from stationers. It is used for attaching pape=
r to=20
notice boards. It is very good for sealing a seismometer case.
 
    Regards,
 
    Chris Chapman