# What is Magnetometer: Definition and 20 Discussions

A magnetometer is a device that measures magnetic field or magnetic dipole moment. Some magnetometers measure the direction, strength, or relative change of a magnetic field at a particular location. A compass is one such device, one that measures the direction of an ambient magnetic field, in this case, the Earth's magnetic field. Other magnetometers measure the magnetic dipole moment of a magnetic material such as a ferromagnet, for example by recording the effect of this magnetic dipole on the induced current in a coil.
The first magnetometer capable of measuring the absolute magnetic intensity at a point in space was invented by Carl Friedrich Gauss in 1833 and notable developments in the 19th century included the Hall effect, which is still widely used.
Magnetometers are widely used for measuring the Earth's magnetic field, in geophysical surveys, to detect magnetic anomalies of various types, and to determine the dipole moment of magnetic materials. In an aircraft's attitude and heading reference system, they are commonly used as a heading reference. Magnetometers are also used by the military in magnetic mines to detect submarines. Consequently, some countries, such as the United States, Canada and Australia, classify the more sensitive magnetometers as military technology, and control their distribution.
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.
In recent years, magnetometers have been miniaturized to the extent that they can be incorporated in integrated circuits at very low cost and are finding increasing use as miniaturized compasses (MEMS magnetic field sensor).

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1. ### Calculating Load with Magnetometer for Synchronous Motor

Looking for any insight on a formula that can be used to calculate the load using a magnetometer sensor for synchronous motor
2. ### I How Does a Vibrating Sample Magnetometer Calculate Magnetic Moment?

In descriptions of a VSM, the induced voltage in a coil is shown to be emf = -dPhi/dt = - (dPhi/dz)(dz/dt). From here, everyone seem to jump to a solution of emf = 2*Pi*A*f*m*sin(2*Pi*f*t). That makes some sense: in this case, you can define z = A*cos(2*Pi*f*t) so (dz/dt) =...
3. ### Maximum detectable distance between magnet and magnetometer

Hi Dear, I have a single-component (Z-Axis) magnetometer with 60nT resolution. I want to calculate the maximum distance that this magnetometer can detect an N52 magnet with a volume of 1 cm³. So I used the following formula and inserted the values, and finally calculated the Z...
4. ### Imperial-Metric Unit conversion for Magnetic Field Gradiometer?

Hi all, I have a question which I think should be a simple solve for most people but I cannot seem to get my head around it. It is a common case in geophysical surveying that a magnetic field vertical gradiometer might be used. This instrument uses two magnetometers separated by a known...
5. ### A Removing frozen field from SQUID magnetometer MvsH data

Hi, I have measured a sample and realized there is a frozen field that remained in the SQUID magnetometer before the MvsH measurements were taken. I am fairly new to using the SQUID, I have plotted the data and if I multiply the applied field by a factor of 0.75 the data matches what I...
6. ### I Understanding Magnetometer & SQUID Property Measurement Systems

Hello, Please I don't get how a Magnetometer property measurement system (MPMS) and a Superconductor quantum interference device (SQUİD) are working, can someone explain it ? Thank you very much
7. S

### Using an electromagnet as a magnetometer

I am new to this site and I am not a physics / engineering professional. Please excuse me if I only have a layman's understanding. I have been trying to make a device to sense a 2 foot long by 2 inch diameter rod at an 8 foot distance (all steel, all ferrious). to be detected. I have tried home...
8. ### Free radicals liquid used in magnetometer

Hi all, I am learning about magnetometers. Esp. those based on the Overhauser effect (https://en.wikipedia.org/wiki/Nuclear_Overhauser_effect). As I understand, they embed a free radical fluid that contains free electrons that gets polarized through a RF field. Do you have any idea what free...
9. ### Data for Earth Orbiting Satellite & Ionosphere: Research Help

HI all, I'm starting by senior research and I am in the hunt of some data! Specifically magnetometer data from an Earth orbiting satellite, I could get the data I think from the http://ppi.pds.nasa.gov/ site but was curious if anyone had an insight or guidance. At my college we have a...
10. ### Audio amplified VSM (vibrating sample magnetometer) sample

Hello, I am trying to get the induced emf reading from a sample in a vsm. A lock in amplifier is being used to read the signal. The problem is that the output voltage fluctuates heavily. Should I apply an audio amplified signal to my sample to make it vibrate ?
11. ### IMU-Gyro Bandwidth and Sensor Fusion on Performance

Hello, For my Master's Project, we are to choose an IMU module to stabilize a platform. You can think of a servo actuated turret, mounted on a Stewart Platform(which will generate the disturbances). The angular position error should be very low and there are both high and low frequency...
12. ### How does an astatic magnetometer work?

The only books I've been able to find are fairly old and are not written very clearly. Would someone be able to put it into A-level terms? I'm not worried about knowing any of the complicated mathematics behind it, only the conceptual side. Although if anyone fancies giving both then that would...
13. ### I'm looking for a simple magnetometer and accelerometer

Hey, I have only a little experience with electronics, and I'm looking for a simple sensor for a magnetometer sensitive enough to detect about a gauss and accelerometer for detecting when something is picked up. As long as I can get a good explanation (data sheets can sometimes be cryptic) I'd...
14. ### FLUXGATE magnetometer - how it works

Assuming that I am looking at an 'ideal' fluxgate magnetometer. I am feeding this transformer an ideal sine wave. The secondary winding output and the primary winding input are fed into two channels of an oscilloscope. A magnetic field from the outside (like Earth magnetic field) is...
15. ### Where Can I Find an Affordable Vibrating Sample Magnetometer Head?

Dear all, We are in need of a vibrating sample magnetometer for our lab. but don´t have the money to buy a new one. We are considering - buy a secondhand one (still expensive) - buy the VSM head and adapt to a existing magnet. If you now where to find one, I would be happy to hear from...
16. ### Compute ΔB seen by a magnetometer flown on a satellite

1. Sample calculation - If a satellite carrying a magnetometer flies at 300km over a current that is flowing at 100km w/ a magnitude of 150 μA/m2 (over a cross-section of ~5 km2), how big a ΔB will be seen by the magnetometer? Assumptions (based on my understanding): -Satellite altitude...
17. ### Attitude reconstruction from magnetometer measurement only

Hi, I am currently trying to reconstruct three dimensional attitude only by using magnetometer measurements with the knowledge of initial attitude. There have been many research conducted on the attitude reconstruction only by magnetometer (or one vector) measurements. For example, this is a...
18. ### Build Digital Magnetometer with Gates - Tutorials/Guides

Hey I am interested in building a device that can give the local magnetic field in 3D. I'd like for the display to be digital not a mechanical gauge. I would not want to use any sensors or microcontrollers for that matter, but make it with gates and everything. If you do know how to make it...
19. ### Electron Precession versus Proton Precession in a Magnetometer?

Hello, Why is it that electron precession is not used in addition to proton precession in a proton precession magnetometer? It seems to me that when the frequencies are emitted as the protons precess that the electrons would do precessing at the same time and provide a secondary frequency to...
20. ### Using a magnetometer to compute the magentic moment of a magnet.

Magnetometer is used to compute the magentic moment of a magnet. In this procedure, we are asked to record the angles of deflection on both sides of the compass heads (that is North and South poles of the compass), since they are vertically opposite angles, they should read the same. Why are...