Since the founding of the Seismological Center in August 1989, it has been actively promoting 'Plan to Strengthen Earthquake Prediction and Establish Seismic Monitoring Network' to expand the seismic monitoring network and collect earthquake data. In the expansion of seismic network, in addition to keeping the original vertical component seismographs in the 19 weather stations, two components of north-south and east-west are added to make each station of the seismic network a complete three-component seismic station. In addition, establish 31 three-component seismic stations, then integrate the Taiwan Telemetered Seismographic Network of the Institute of Earth Sciences, Academia Sinica and the Chiayi-Tainan local network of National Chung Cheng University into the real time seismic monitoring network of 71 seismic stations for intensified operation.

The S-13 (Portable Short-period Seismometer) is the instrument adopted by the Central Weather Administration in 1982 to renew earthquake observation equipment. It is of solid construction and good stability with its internal structure of spring, weight and coils.

When the earthquake hits, the ground motions relative to the heavy weight of S-13 will produce with electrical voltages that are transformed into seismic signals in periods of 0.91~1.33 seconds with the normal period at 1 second. As S-13 is an extremely sensitive sensor, to reduce the influence of any non-seismic vibration of the ground, it is preferable to place it on the platform in the seismology room of the manned weather station. Meanwhile, it shall be located in places that operators rarely pass to avoid any internal damages resulting from crushing. It shall be placed on the concrete base in the unmanned seismic monitoring station.

After the digitalization of seismic signals from the seismic monitoring stations in north and middle Taiwan, such data are directly transmitted back to Taipei via cable by MODEM at a speed of 4800 bits. The signals from seismic monitoring stations in Hualien region and South Taiwan are first transmitted to Hualien Weather Station and the Southern Region Weather Center, and then transmitted to Taipei Central Station via T1 cable.

After all the digital signals from various seismic monitoring stations have been transmitted to the Seismological Center, the data are first processed by digital signal receiver and then processed by various data receiving and processing systems (such as NSDP and ICP) for seismic event detection and continuous recording. Then, the data are converted to the original signals produced by the seismograph in the digital/analog converter. Such signals can be displayed in the multi-channel recorder.