WIM statistics used in this study were collected with equipment from Bridge Weighing Systems, Inc., of Cleveland, Ohio. The portable 2100 FCS is capable of handling multiple channels of data and downloading data stored in local memory to a notebook computer in the field. The unit is impervious to the elements due to its modular aluminum packaging. One of the main reasons the 2100 FCS was selected over other data acquisition equipment is its small size. Unlike larger systems, the 3 inch by 5 inch by 8 inch tall system is light enough and small enough to carry up a ladder for placement under the bridge.
Vandalism is prevented as the system is inconspicuous.
The system, which consists of a field computer, memory module, communications module, and four strain gauge modules, fits into a small black metal box about the size of a tool box. Another reason for using the SoMat system is its ability to perform data analysis simultaneously with data acquisition. This system was programmed to process a rainflow algorithm as it collected strain data at a rate of 200 Hz. Because the field computer executed the rainflow algorithm as the data was sampled, it was possible to collect approximately 4.5 billion cycles per channel. Following collection, the data was reviewed and downloaded to a notebook computer for storage, processing, and plotting.