Information gathering apparatus which has functions to store the data measured by remote monitoring and to send a stored data upon request, namely, electronic recorders for storing and archiving information related to temperature, pressure, flow and other physical data from sensors; data acquisition apparatus which has functions to store the data measured by remote monitoring and to send a stored data upon request, namely, mobile data receivers and mobile data receivers using communication networks; data loggers, namely, electronic measuring devices, namely, temperature indicators, temperature sensors, pressure gauges, pressure indicators, flow meters; data collecting devices, namely, apparatus for recording data in the nature of temperature, pressure, flow and other such physical data from sensors; record and display units of measurement data, namely, video monitors for recorded wave forms of measured data and measured values; computer programs for analyzing measured data, namely, computer software for use in database management, for use in logging, analyzing, manipulating and managing the temperature, pressure, flow data for use in the process data field; measuring apparatus, namely, signal analyzers for analysis of abnormal conditions of signals of measured data related to temperature, pressure, flow and other physical data from sensors; electric and magnetic meters and voltage testers