Compared with their predecessor, the new systems (DataStation, DataCraft) that we have developed offer various advantages such as an increase in the number of types of seismographic equipment applications, the provision of an early earthquake detection process function and the capability to process a large quantity of data collectively. Early earthquake alarm seismographs will be installed along the meter gauge lines in the near future. Before the existing seismographs are replaced with these early earthquake alarm seismographs, we should confirm the suitability of the new system based on the analysis of past data.