Magnetic Gradiometers
A magnetometer measures magnetic field strength at a specific measuring point. In some applications, it is more useful to measure how much the strength of a magnetic field changes between two specific points. For such a measurement of the change in field (the "gradient" of the field), a Magnetic Gradiometer is the ideal instrument.
A common application of a gradiometer is the location of features or objects that are invisible to the eye, but have magnetic properties; underground features are a typical example. The features magnetic characteristics will cause a disturbance in the earth's magnetic field in an area around the object. This disturbance can be detected as a magnetic field gradient, by a gradiometer.
Single-axis gradiometers measure magnetic gradient in a single vector-direction. They are quick to setup, lower cost than the three-axis equivalent, and produce data that is straightforward to analyse. Three-axis gradiometer measure the gradient in the x,y and z directions and can yield more information about features, but data processing is significantly more complicated.
Bartington Instruments produce single-axis and three-axis fluxgate gradiometers.
Click on the links below for more details of the instruments:
Grad601 Single-axis Magnetic Gradiometer
The Grad 601 is a single-axis, vertical component, fluxgate gradiometer with data logger and either one or two cylindrical sensor assemblies for use in geophysics and archaeology. Each sensor assembly contains two fluxgate magnetometers with a one metre vertical separation together with electronics and non-volatile memory for calibration data. The system provides an enhanced depth response, exceptional stability and electronic adjustment.
Grad-03-500M Three-axis Marine Gradiometer
The Grad-03-500M is a three-axis gradiometer, suitable for underwater use. Intended for use with a separate Analog Correction Unit, which facilitates sensor scaling and alignment correction, and includes three LCD displays for measurement display.
The gradiometer is suitable for ROV mounting and operation to a depth of 5000 metres. It can be used for depth of bury measurements and geophysical surveys, where the three-axis information will have a particular advantage in determining the direction of an anomaly.
A common application of a gradiometer is the location of features or objects that are invisible to the eye, but have magnetic properties; underground features are a typical example. The features magnetic characteristics will cause a disturbance in the earth's magnetic field in an area around the object. This disturbance can be detected as a magnetic field gradient, by a gradiometer.
Single-axis gradiometers measure magnetic gradient in a single vector-direction. They are quick to setup, lower cost than the three-axis equivalent, and produce data that is straightforward to analyse. Three-axis gradiometer measure the gradient in the x,y and z directions and can yield more information about features, but data processing is significantly more complicated.
Bartington Instruments produce single-axis and three-axis fluxgate gradiometers.
Click on the links below for more details of the instruments:
Grad601 Single-axis Magnetic Gradiometer
The Grad 601 is a single-axis, vertical component, fluxgate gradiometer with data logger and either one or two cylindrical sensor assemblies for use in geophysics and archaeology. Each sensor assembly contains two fluxgate magnetometers with a one metre vertical separation together with electronics and non-volatile memory for calibration data. The system provides an enhanced depth response, exceptional stability and electronic adjustment.
Grad-03-500M Three-axis Marine Gradiometer
The Grad-03-500M is a three-axis gradiometer, suitable for underwater use. Intended for use with a separate Analog Correction Unit, which facilitates sensor scaling and alignment correction, and includes three LCD displays for measurement display.
The gradiometer is suitable for ROV mounting and operation to a depth of 5000 metres. It can be used for depth of bury measurements and geophysical surveys, where the three-axis information will have a particular advantage in determining the direction of an anomaly.
