The DS840 fixed extrusometer has been designed for the deformation detection of the advance face during tunnel excavation.
The instrument consists of a anchor and a measuring head installed at different depths, for example the anchor to 12m from the front while the head 6m from the front.
Inside the head there is a DS810 displacement transducer of 200mm and a radio transmitter that allows record movements in real time, without having to interrupt work.
The anchors are inflatable allowing a punctual cementation that allows to consolidate only the anchoring to the ground, without cementing the whole hole. Another inflatable anchor is connected to the head ensuring a better adherence to the ground.
The radio transmitter is equipped with an antenna placed inside of a metal protection tube.
The head is made of aluminum and stainless steel, to ensure precision and efficiency even in the long term.
The measuring heads are designed to have from 1 to 4 measuring points .