DATA PRESERVATION METHOD IN DATA LOGGER

PURPOSE:To provide a data preservation method in a data logger capable of preserving the trend of original analog output with a little memory capacity. CONSTITUTION:A data gathering period is divided into the evaluation sections A to G of an appropriate time period each. The analog values of the analog output are sampled and gathered at plural sampling timings in the respective evaluation sections A to G. The maximum displacement width of the sampled and gathered analog values is calculated for the respective evaluation sections and when the size of the maximum displacement width is larger than a stipulated value set beforehand, all the sampling data of the evaluation sections are recorded and preserved. When the maximum displacement width is smaller than the stipulated value, only the representative data of the respective evaluation sections are recorded and preserved.