Development of a Multi-Channel Array Resistivity Method Instrument System

Abstract

Application scenarios and experimental methods in the field of modern electrical exploration are becoming increasingly complicated, expanding requirements on instrumentations. Currently, the commonly used Resistivity method instrument systems are mostly single-channel transmitting and receiving, which lowers the measurement efficiency. The multi-channel array Resistivity method instrument system developed in this paper adopted an improved automatic measurement method to realize array synchronous transmitting and receiving, which effectively improve the measurement efficiency. The instrument consists mainly of two parts: a transmitter and receiver subsystems. The transmitter subsystem realizes array transmitting through centralized electrode units or serial electrode management nodes. The former can support up to 256 electrodes with a maximum transmit power of 600W; the latter can support up to 65,535 electrodes with a maximum transmit power of 5kW. The receiver subsystem consists of multiple 8-channel receivers. The Root Mean Square noise of the receivers is lower than 9.38 microvolts, the dynamic range is better than 120dB, and the isolation between channels is better than 119dB. Combined with a built-in 4G and Wi-Fi module, it can achieve real-time monitoring of data quality and cloud storage functions. The results of the water tank comparison experiment between the developed instrument and GRx8-32 showed well consistent By applying the developed system to the monitoring of the perfusion process of structured cementitious materials, the relative changes in resistivity of the perfusion process can be visually monitored, which lays a foundation for the application of the instrument in two-dimensional and three-dimensional detection and time-shift monitoring in other fields.