Folowrd company has produced diﬀerent models of extensometers. This equipment is used in great scale in diﬀerent underground projects, building’s foundations and other situations where there is a need for constant monitoring of deformations in diﬀerent levels of ground. Extensometers anchors types, rod lengths and material are designed according to ground condition of project location. The anchors are borros anchors, packers or groutable. In week ground conditions or loose soils which grouting hasn’t sufficient strength for fixing the anchors, the hydraulic anchors are best alternatives.
- All kind of ground movements
- Deformation of diﬀerent structures foundations
- Deformation of concrete piles
- Fracturing in the roofs and walls of underground caverns
Anchors are parts of each rod that are in contact with their sour rending ground by grouting, packering or hooking.
This type of anchors is for using in non-cohesive soils and compact rocks.
Borros type anchors are used for soft soils and clays. Their activation is by hydraulic pressure.
Used in soft soil conditions, granular materials and are used typically in up-hole installations. inflated with cement by injection tube.
Rods are used to connect the anchors to the reference head and are available in rigid or flexible form.
Made from stainless steel and is available in 1,2, 3…6 meters. Higher lengths are obtained by threaded connection.
The glass & carbon fiber rods are a continuous length factory produced to meet the project requirements
For moving freely, rods need sleeves in place. This is because, one of the installation step, is grouting in grout anchors. The two options are possible:
Made from rigid PVC or Stainless Steel.
Made from the flexible nylon.
Reference head is apparent part of extensometer while rods are embedded. Heads are available in the following types:
The differences in length can be measured using mechanical measuring tools. and is applicable where there is easy access to the extensometer.
Used when access to the reference head is difficult or where continuous monitoring is required. The sensors are connected to rods in this part. The output signal of measured movement is converted to length by a digital datalogger.
In case of electrical head, Folowrd’s sensors with different ranges can be used. LVDT and linear potentiometers are available for this purpose. Also mechanical reading without using sensors can be done by using accurate mechanical measuring tools.
- All sensors are tested and calibrated.
- All instruments are installed by Folowrd experienced staffs.
|LVDT||Up to 150mm|
|Linear potentiometer||Up to 150mm|
|Electronical LVDT Head characteristic|
|Displacement Range||1mm to 150 mm depend on customer order|
|Channel Points||1 to 5|
|Typical non-linearity||± 0.1 to ±0.08 depend on Measuring range|
|Resolution||0.1 … 0.001 mm depend on Measuring range|
|Total accuracy (linearity+hysteresis+repeatability)||<±0.09% FS|
|Supply voltage||24 VDC|
|Storage temperature||-55ºC to +90 °C|
|Operating temperature||-40ºC to +125 °C|
|Logger and Display||Compatible with RUD600,RUD400, Readout units|
|MATERIAL||DIAMETER||YOUNG’S MODULUS||EXPANSION COEFFICIENT|
|Stainless steel||6 mm||200 GPa||16.0 ppm/C|
|Fiberglass||5 mm||20 GPa||3.0 ppm/C|
|Carbon fiber||5 mm||130 GPa||<1.0 ppm/C|
|Length||Depend on customer order|