Extensometers and Settlement Gauges




Our magnetic probe, of the inductive type is designed by us for use in settlement gauge columns made of PVC, ABS or plastic material and equipped with iron rings positioned along the length of the column. The probe is able to slide along its length and follow the movements of the ground. The probe is fitted with a sturdy electric cable, inextensible and with reference marks every 50 cm, which in addition to allowing transmission of electric signals emitted by the probe, also supports it during its descent and ascent inside the column during monitoring. During its descent and ascent, the probe intercepts the various iron rings and sends a signal that identifies their exact centered location. The exact position of the probe is measured by the cable (graduated in millimeters) which holds it.



Road and railway embankments


Land surrounding excavation areas and diaphragms





Features and Benefits

Does not require magnetic rings

Precise and reliable over time

Easy to use

For use with thick and large diameter pipes


Measuring principle

The magnetic probe, intercepts, during its descent and its ascent, the various iron rings positioned along the settlement column, sending a signal that defines the exact centered position of the probe inside the rings. The measurement of the position of the probe, and therefore the position of the iron ring is determined via the cable holding the probe. All measures refer to a well-defined measuring point on the head element of the settlement gauge.

The probe allows centering of the ring with high resolution and repeatability and therefore with very precise definition of position, accuracy to about 2mm. The accuracy of measurement depends on cable maintenance and on the operator performing the readings. With good training, a measuring accuracy of 1mm can generally be achieved.

In the case of larger diameters of the settlement column, it is necessary to equip the probe with a device to increase its diameter.
The probe has an external diameter of 57mm and is generally used in settlement or inclinometric columns.

The electric cable is supplied with a special cable reel containing the signaling device.
A digital display indicates the position of interception of the metal rings.
Using the battery test function, charge level and battery status can be viewed on the display. Two beepers indicate the passage of the probe into the top and bottom of the iron rings.
It is recommended to charge the battery after use.
The instrument is composed of:

  • Magnetic induction probe
  • Cable with kevlar core with marker every 50 cm; 50m length (standard), 100m on request.
  • Roller cable reel with logger/sensor and built-in battery
  • Charger
  • Stainless steel leveling staff, with graduations in millimeters, length 50 cm

Technical Specifications

Material Stainless steel and PVC
Accuracy and repeatability of detection 1mm
Inextensible cable With marking every ½  meter
Control Unit Inserted in the cable reel
Sensor Inductive
Display for the ring detection On the reel
Settlement Column PVC – ABS

Accessories and related products

Intermediate element for settlement column, with fixed junction sleeves In PVC, L = 3 meters, provided with fixed junction sleeve
Intermediate element for settlement column, with sliding junction sleeves In PVC, L = 3 meters, provided with sliding junction sleeve
Head Element with cap To close and protect the settlement column
Bottom Element As final element with fixed reference
Simple ring in galvanized iron For installation in bore holes
Simple ring in galvanized iron with plate For the installation in embankments under construction


Technical Assistance

If you have any requests or questions about our instruments or if you have special needs that require different solutions from the standard, please contact us. Our team will provide all the necessary information and will be very happy to work with you to study, develop and customize instruments and solutions suitable for your specific needs.



All information in our datasheet is subject to change without prior notice.

Please check the datasheet/details carefully and contact Pizzi Instruments for further information.