永年変化観測用超低速記録計の開発

概要

論文の詳細を見る
Typical recorders commonly used now in Japan to record low speed phenomena have chart speeds of several centimeters per hour. These chart speeds are convenient to see daily variations such as earth tides, but are not adequate for the purpose of glancing the variations of longer periods. In order to see directly the secular variations of very slowly progressing phenomena such as crustal movements, a recording system which has ultra-low chart speed (several cm/month) and ultra-low frequency characteristics was developed. The method adopted here is to plot the sum of the data which was sampled in the past 24 hours, while the recorder is driven intermittently. The features of this system are as follows: (1) Owing to its ultra-low chart speed, we can directly see the progress of the phenomena within a few days or a few months. This may offer useful information for the short period earthquake prediction. (2) Owing to its ultra-low frequency characteristics, we can pick up the signals which are buried in daily disturbances of large amplitudes. (3) Owing to the durability of the recording chart, we can be free from frequent maintenance of the system. (4) As the system is constructed by use of a microprocessor, we will be easily able to correspond to future demands such as improvement of the data-smoothing algorithm.
1980-08-25