Wide-Area Wireless Data Logging for TSF
Requirements for the loggers included long-range radio communication and efficient battery-powered operation.
The loggers had to deliver measurements at temperatures well below zero for much of the year.
Challenge
GEO-Instruments Canada was tasked with installing a monitoring system at a tailings dam attached to a major iron ore mining operation in northern Quebec, Canada.
It was a challenging assignment: the tailings dam stretches over several square kilometers. Any monitoring solution would not only have to operate reliably over long distances but also keep working at temperatures well below zero for much of the year.
Solution
GEO-Instruments Canada tested and then proposed deploying wireless LoRa loggers from Worldsensing. The compact, self-powered wireless LoRa loggers are designed for energy efficient operation and capable of transmitting measurements over long distances.
The radios operate at 900 Mhz, which provides excellent signal penetration, and use robust signal modulation to achieve reliable long range transmissions up to 9 miles.
The transmitted measurements are received by wireless gateways, which act as a secure bridge between the wireles loggers and the mine's network. Management software provides the status of the devices in the network and enables integration with other software.
Implementation
The first step was automating operation of tens of vibrating wire piezometers that had been installed at critical areas of the dam in previous years and were read manually. Some areas included natural barriers that could interfere with radio transmissions.
To ensure the reliability of communications, GEO increased the logger sampling and transmission rates so that at least one reading per hour would get though.
The loggers were installed close to the sensor locations, minimizing cable runs. No external power supplies were needed, since batteries would provide many years of operation. However, enclosures and external antennas were provided for all the loggers.
Results
- The wireless data acquisition reliably delivers measurements from all monitoring locations, even in winter, when ambient temperatures can drop to -40ºC
- Continuous monitoring provides up-to-date measurements and contributes to trouble-free mining operations.
- The automated system has eliminated most manual monitoring, enhancing the safety of technicians and reducing costs.
“We haven’t had to change the batteries yet, due to energy-efficient LoRa loggers and VW piezometers. We expect to easily achieve a 10-year battery life.” - Vincent Le Borgne, R&D Manager, GEO-Instruments Canada (formerly GKM Consultants)