Seismology Instruction with the AS 1

6. Carefully swing the boom up until it is possible to position the damping fl uid container 

under the damping vane.  Do not fi ll the container before it is positioned correctly.             

CAUTION:  Do not release the boom arm abruptly and allow the magnet to hit the coil.  The 

equipment is sensitive; handle and adjust the parts carefully and gently.

7. Add fl uid to the damping fl uid container.  The fl uid level should be 1 cm (3/8 inch) below 

the top of the container.  For proper damping, the fl uid should be:

   1/2 STP oil treatment and 1/2 10w40 synthetic motor oil for the thick spring units 

(spring diameter of 8 mm)

   1/3 STP oil treatment and 2/3 10w40 synthetic motor oil for the thin spring units 

(spring diameter of 4 mm)

8. The boom arm must be level to accurately 

(This position may vary)

record vertical motion.  Begin by positioning the 

bubble level on the boom, as shown in Figure 6.        

Add or remove washers from the upright bolt and 

if needed, add one or two washer(s) along the 

boom until the boom is level.  Move the washers 

and the bubble level along the boom arm to fi ne 

tune the leveling.  The washer and bubble level 

remain on the boom arm to keep it level.

Figure 6

9. Rotate the bubble level 90 degrees on the boom.  Adjust 

the base leveling screws until the bubble is again centered.  

Rotate the bubble level 90 degrees back to its starting      

position.

10. Check that the magnet is still centered above the coil.  

Center the magnet over the coil by sliding the knife edge 

at the support post (Figure 7).  The boom arm should move 

freely up and down and the magnet should not touch the coil.  

Figure 7

11. Attach the paired shielded coaxial cable to the interface 

box.  To attach a wire to a post the wire must pass through the 

hole on the post (Figure 8) then tighten the plastic knob.

The center conductor of the 

signal cable (uninsulated wire) 

should be connected to the 

ground terminal (black post) on 

the interface box.  The remaining 

two insulated wires should be 

connected to the two red posts 

Figure 8

(Figure 9).  Tighten until snug.

Figure 9

AmaSeis Version 1.0 Level 2005.05.19

2.3