Cone Penetration Testing

Magnetometer

Magnetometer surveys are used to identify presence of ferrous metals in the ground, in particular unexploded ordnance, buried tanks, pipes piles or drums. Our magnetometer set up is mounted within a traditional cone apparatus and is ultra-sensitive with a tensionband of 300,000nT (nanoTesla) mounted within a 44mm diameter cone which minimises soil disturbance. The instrument has a measurement range of 500mm giving a focussed assessment and experiencing less disturbance from far-field objects.

Cone Penetration Testing

Magnetometer

Cone Penetration Testing

Magnetometer

Magnetometer surveys are used to identify presence of ferrous metals in the ground, in particular unexploded ordnance, buried tanks, pipes piles or drums.

The Earth’s magnetic field(the so-called magnetosphere) is homogeneous in signal strength and direction but varies from place to place, for various reasons, such as homogeneity of the rock and the interaction between charged particles from the sun and the magnetosphere.

When a ferromagnetic object enters this homogeneous field, the object’s own field becomes dominant relative to the local magnetic field of the earth, causing a weak disturbance of the magnetic field which can be picked up by a magnetometer. As the distance from the object increases, the disturbance decreases. The degree of disruption depends on several factors. The most important factors are the size and orientation of the object to be detected and the permeability of that object. The larger the object to be detected, the greater the distance at which the object can still be detected.

The Triaxial Magnetometer Module is specially designed to detect magnetic anomalies in the magnetic field created by possible buried or underwater ferromagnetic objects. On average a vertical cylinder with a diameter of approx. 2 meter is measured per probe (sensitivity v/s distance v/s object size). Creating the ideal tool for deep UXO detection in a real-time and non-real-time set-up with software that has the option to upload a “borehole” plan and GPS location registration to structure the data capture and optimize production.

Our magnetometer module is available with a signal Triaxial sensor and a double (differential) Triaxial sensor set-up and can be fitted with either a non-magnetic conical tip only or it can be mounted on top of a P15CFPTuxy electrical pore pressure CPTu cone equipped with special non-magnetic wear parts and a special connector to make the electrical connection between the CPTu cone and the magnetometer module to perform combined CPTs.