- Aim of monitoring is to receive data to design parameters of bolting system such as bolts capacity, length, pattern and if necessary supplementary cable bolts.
Basic instrument is strain gauge bolt and extensometer.
For routine visual control telltales are used.
- Tell-tale are used for routine, permanent measurement of strata movement throughout bolted roadways. Instrument is easy to install.
There can be single, dual and multi height telltales. Available is also telltale with water diverting system. Where when and how to install instruments is determined by authorized expert.