Operation and Maintenance Manual
Geotomographie GmbH, Am Tonnenberg 18, 56567 Neuwied (Germany)
Tel.: +49 2631 778135 email: info@geotomographie.de
The reference direction of the geophone unit is the axis of the H1 element. This direction can be
followed along the markings on the rotating string (see Figure 2).
Figure 2: Marking along the rotary string is aligned to the H1 geophone
A seismic impulse in the direction of the marker line will produce a positive rising signal. A test
pulse by tapping the centre of the geophone unit with a simple ballpoint pen or pencil will give
such a signal.
All other H-components can be tested in the same way. The reference direction is H1 plus 90° in
a clockwise direction as seen from the top of the geophone.
The bladder tube is located between the PVC cylinder and the outer steel casing. Replacement of
the rubber tube is described in Chapter 3.1.
1.2 Rotary pipe string
The rotating tube has two functions
(1) supply air and protect the signal cable; and
(2) to orientate the borehole probe within the borehole.
The rotary pipe string can be coiled up but it is stiff for rotation. The string is terminated at the
surface by the probe and a splitter.
1.3 Surface splitter and seismograph connection
A surface PVC unit is designed to be split between the air supply and the signal cable. The signal
cable ends in a connector box and connection can be made to seismograph (see Figure 3).
