Extensometer Model EDS-71V/EDS-71P (MTI.EWS.ER.M-EDS-71V/EDS-71P) The borehole extensometer measures extension
(displacement) that takes place with time in a bored hole
or in several bored holes in a rock mass. The single point
borehole extensometer consists of a single anchor and a
reference.
They help to accurately measure distance between the
anchors with respect to the reference and monitor its
relative displacement with passage of time. It is usually
assumed that the anchor is in stable ground and so any
change in the anchor spacing is interpreted as sag of the
roof bed, movement of side wall or slope, settlement of the
foundation etc.
Extensometer Model EDS-71V/EDS-71P
• Range (mm) 50, 100, 150
• Accuracy ± 0.2 % fs normal, ± 0.1 % fs normal
• Sensitivity ± 0.02 % fs
• Non linearity ± 0.5 % fs
• Temperature limit -10 to 80°C (operational)
• Thermistor YSI 44005 or equivalent (3 kOhms at 25°C)