4.2 The fixed mounting of the seismograph - pendulums in our station  [ cont'd (b) ] 3/3

The velocity to voltage converter unit of the east-west seismograph is shown in the next photograph. The magnet, which was once part of a mass-spectrometer that was kindly donated to the project by Dr. Dittmer of the Siemens Scientific Research Laboratory in Aachen.

Fig. 35: The velocity to voltage converter unit of the East-West seismograph

The housing of the paper-recorder of our station in one of our halls was donated by the father of one of our students. Here we can see when an earthquake has taken place. The feed-velocity of paper is approximately 1cm per minute, consequently the looped tracker paper of circa 4.8 meters length takes about eight hours for a full cycle. During this cycle the recording nib of the TY-writer is moved 1cm to the right.

The paper is thus filled spirally during the course of a week. At the end of the week the nib is placed between the first two old lines, a pencil with a different ink-colour is inserted and in this way the paper can keep recording for two weeks running.

Fig.36: The sight-recorder of the earthquake station at the MGM Monschau