NUR Extensometer
An instrument for automated displacement monitoring based on a laser rangefinder. It measures the distance to a reflective surface at high frequency and sends the data to a server
Specifications
- Measurement range
- 0–40 m
- Measurement accuracy (RMS)
- 1 mm
- Resolution
- 1 mm
- Measurement rate
- configurable, from 1 s⁻¹
- Online displacement monitoring
- ~1 s latency
- Data transfer
- GSM (radio and other channels planned)
- Alerts
- Telegram bot, SMS, email
- Standalone power supply
- 5 V
- Autonomous operation
- with a solar panel
- Battery capacity
- 38900 mAh (144 Wh)
- Water and dust protection
- IP65
- Laser class
- 2
Applications
The NUR extensometer monitors mining-induced cracks and crack opening, convergence of underground openings, and rockfalls on pit slopes and in the walls and roof of underground openings.
The instrument is accurate enough to pick up displacements at an early stage of failure. Because it measures at a high frequency, it can determine displacement rates, which makes it possible to predict the time of failure and raise alerts when critical rates are reached, much like interferometric radars do.
So far the instrument has been tested in open pits, where it has proved effective. It has not yet been tested underground.
Installation
- The instrument sits on a dedicated bracket that locks it in place and rotates 360°
- A solar panel keeps it running continuously and fully automatically
Monitoring
Extensometer readings are plotted in our web service, which shows distances, displacement rates and other data in real time. You can set up alerts for when critical rates are exceeded.
