Tell Tale Extensometer are used to measure the movement occurring in Rock bolted tunnel or mine roadways by the help of color bands.
The Rotary Tell tale Extensometer of PMT overcomes the problems with Mechanical Tell tales installed in the roadway roof which has difficulty in reading the graduated scale in high roadways. This instrument converts roof movement into rotation of a pointer round a dial and magnifies the movement.
- - Reliable, low cost, accurate.
- - High accuracy and simplicity in readings.
- - Portability of probes.
- - Versatility in component assemblies.
|No. of Anchors||1|
|Measuring range||Up to 30mm|
|Hole depth||1 to 10m (more if required)|
|Hole diameter||37mm – 57mm|
|Access Tube||25 – 30mm PVC Pipe|