What is an Overhauser magnetometer?
Background: The Overhauser magnetometer based on dynamic nuclear polarization (DNP) effect is a high-precision device for weak magnetic field measurement. The Larmor precession of excited protons around the geomagnetic field can generate a free induction decay (FID) signal.
How do you choose a magnetometer?
When selecting magnetometers, buyers should consider the specific type of magnetometer technology, its form, its outputs and interfaces, and its design specifications.
- Type. There are two basic types of magnetometers: scalar and vector.
- Form.
- Outputs and Interfaces.
- Design Specifications.
- References.
How does a proton precession magnetometer work?
The proton precession magnetometer operates on the principle that protons in all atoms are spinning on an axis aligned with the magnetic field. Ordinarily, protons tend to line up with the earth’s magnetic field. When this new field ceases, the protons return to their original alignment with the earth’s magnetic field.
How accurate is a magnetometer?
Because the precession frequency depends only on atomic constants and the strength of the ambient magnetic field, the accuracy of this type of magnetometer can reach 1 ppm.
What is a near bottom magnetometer used for?
On land, magnetometers can be used to find iron ore deposits for mining. Under the sea, marine geophysicists, ocean engineers and nautical archeologists use marine magnetometers to detect variations in the total magnetic field of the underlying seafloor.
What is the use of proton magnetometer?
A proton magnetometer, also known as a proton precession magnetometer (PPM), uses the principle of Earth’s field nuclear magnetic resonance (EFNMR) to measure very small variations in the Earth’s magnetic field, allowing ferrous objects on land and at sea to be detected.
What does a proton precession magnetometer measure?
Introduction: A Proton Precession Magnetometer is an instrument that measures the scalar intensity of the local magnetic field and relies upon the proton-precision measurement technique.
What can a magnetometer detect?
Magnetometers can be used as metal detectors: they can detect only magnetic (ferrous) metals, but can detect such metals at a much larger depth than conventional metal detectors; they are capable of detecting large objects, such as cars, at tens of metres, while a metal detector’s range is rarely more than 2 metres.
What does a proton magnetometer measure?
The proton magnetometer measures a radio-frequency voltage induced in a coil by the reorientation (precession) of magnetically polarized protons in a container of ordinary water.
Why does precession occur in MRI?
In addition to alignment of nuclei with a magnetic moment, application of an external magnetic field will produce a secondary spin or wobble (precession) of nuclei around the main or static magnetic field. The precessional path around the magnetic field is circular like a spinning top.
What kind of magnetometer is the gem Overhauser?
GEM’s Overhauser Magnetometer system is a revolutionary geophysical instrument developed by GEM to offer a rugged, low power, and sensitive alternative to Proton Precession and some other alkali vapour magnetometers. GEM’s GSM-19 (Overhauser) magnetometer is a primary standard in mineral exploration and magnetic observatories.
How is the Overhauser magnetometer used in archaeology?
As a standard for magnetic observatories, this system has proven itself – for its high sensitivity, absolute accuracy and long life. Overhauser magnetometers are also used in archaeology, pipeline mapping, UXO detection, and other engineering and environmental applications.
What are the features of a walking magnetometer?
A walking magnetometer/gradiometer is a high-sampling system capable of acquiring nearly continuous data. Key features are related to data quality, cost control and productivity as follows: 5 samples per second acquisition for higher productivity (either by operator or on towed vehicles) and more data for decision-making
Which is the best magnetometer for mineral exploration?
GEM’s GSM-19 (Overhauser) magnetometer is a primary standard in mineral exploration and magnetic observatories. As a standard for magnetic observatories, this system has proven itself – for its high sensitivity, absolute accuracy and long life.
