Wireless Network Node to Monitor Stress in Steel Structures

The article presents a wireless measuring node operating in a system monitoring stress in steel structures. Stress sensor is a foil strain gauge, working in a half-bridge circuit. The presented node is based on the microcontroller Atmeg 8, and the data transmission modem used 433 MHz band. The use of 22-bit ADC allows for measurement of the stresses at 4 u-strain resolution. The article discussed the structure of the node, installation problems in the actual real projects and the results of laboratory tests. Based on the research it can be concluded that the measuring node can be used to monitor the load caused by residual snow on the steel roofs.