The Reliability of Low Cost Data Logger for Active Seismic (Surface-Wave) Data Measurements

Abstract

Seismic data acquisition needed a relatively fast data logger and multi channels input capability. For this purpose, we construct a measuring instruments based on low cost voltage data logger DI710ULS from DATAQ. The sensors (geophones) have 4.5 [Hz] natural frequency, produce an alternating electric voltage at rate 28 [V/m/s]. The ground shaking / velocity rate of active seismic surface-wave measurement from 5 kg hammer, at 3m distances, is less than 2 [mm/s]. This will produce an alternating voltage at less than 100 [mV].The active seismic surface wave measurements need around 1 ms time sampling for every channels and this instruments can record 7200 data for 8 differential channels, which is sufficient for this purpose. The DI710ULS has a standalone capability and all digital data were recorded in SDcard, whose very light and compact for field acquisition. By only 14[bit] DAC, the data shows reliable and seems good enough by 12.2 [μV] sampling. The data collected by using this data logger were successfully processed for surface wave analysis, and giving a reasonable result.