Abstract:
In order to meet the need of monitoring the corrosion status of metal materials in the outdoor environment, a remote micro resistance monitoring scheme based on TCP/IP is proposed. The monitor hardware consists of STM32F4 microprocessor, AC constant current source, data acquisition, network communication module,etc. The principle of micro resistance measurement is using the digital correlation algorithm to eliminate the impact of noise in the signal to be measured, the digital cross correlation are between the data collected from the signal on resistance to be measured or the data collected from the signal on standard resistance and the data from sine wave reference signal with the same frequency respectively, then using Ohm's law to obtain the resistance to be measured. The value of resistance to be measured is uploaded to the PC through the network. The experimental results show that the monitoring system can achieve high-precision measurement of small resistance in the range of 1 μΩ to 2 Ω. The remote PC server program can control the automatic detection performed at the set time, which provides a possible way for remote real-time monitoring of corrosion status of metal materials.