# Measuring Magnetic Field Strength with Hall Probe

• medusa
In summary, the conversation discusses the use of two permanent bar magnets to create a magnetic field and the need to use a Hall probe to measure its strength. The problem arises when trying to calibrate the probe, as it requires current to flow through it to excite the electrons and obtain a Hall voltage reading. However, it is unclear if the Hall probe requires an external power source or if it has a battery already. Further clarification is needed on the appropriate settings for calibrating the probe.
medusa
there are two permamnent bar magnets put with a south pole facing a north pole.
there is a magnetic field in between the bar magnets.
i need to use the hall probe to measure the field strentgh.
the probe measures a hall voltage and i can convert this to magnetic field strength values using the calibration graph i have.

the problem i have is that i think current must flow through the hall probe so to excite the electrons so they can be deflected once the probe is in the field. otherwise i will not be able to get any hall voltage reading.
can someone explain to me that should there be current flowing through the hall probe? for me to get hall voltage readings or can i just place the hall probe in the field without any current flowing through the probe? and it just bieng connected to a voltmeter.

medusa said:
there are two permamnent bar magnets put with a south pole facing a north pole.
there is a magnetic field in between the bar magnets.
i need to use the hall probe to measure the field strentgh.
the probe measures a hall voltage and i can convert this to magnetic field strength values using the calibration graph i have.

the problem i have is that i think current must flow through the hall probe so to excite the electrons so they can be deflected once the probe is in the field. otherwise i will not be able to get any hall voltage reading.
can someone explain to me that should there be current flowing through the hall probe? for me to get hall voltage readings or can i just place the hall probe in the field without any current flowing through the probe? and it just bieng connected to a voltmeter.

For the magnetic field to act on the charge carriers in the Hall probe, the carriers must be moving. If not, the v x B term in the Lorentz force will be zero and nothing interesting will occur. And to make the charge carriers move, you have to supply a potential difference to cause a current to flow.

Zz.

ok
to calibrate the probe i will be using a solenoid. so there must be current flowing through the solenoid to cause a magneic field and also current flowing through the probe to cause movement of the electrons.
but the current in the probe should be small and steady? as it is only required to cause movement of the electrons.

from this link you can see they are calibrating the probe but no mention of any current flowing through the probe.

http://dept.physics.upenn.edu/~uglabs/lab_manual/magnetic_field.pdf

medusa said:
ok
to calibrate the probe i will be using a solenoid. so there must be current flowing through the solenoid to cause a magneic field and also current flowing through the probe to cause movement of the electrons.
but the current in the probe should be small and steady? as it is only required to cause movement of the electrons.

from this link you can see they are calibrating the probe but no mention of any current flowing through the probe.

http://dept.physics.upenn.edu/~uglabs/lab_manual/magnetic_field.pdf

Humm... is it possible that there are Hall Probes that don't need to be attached to a power supply? I'm trying to think...

It is possible that all you need to do is set it to a particular current value and leave it at that for your calibration and measurement. The manufacturer may also provide the working settings.

Now, are you sure that these Hall probes do not have any batteries in them?

Zz.

ok i will try to find and see what settings the manufacturers give.

they give no current rating.
im sure without current no charge will flow.
but to calibrate it should constant current be passed through the probe?
like you could make a steady current of 1,2 or 3 amps to flow etc.
but this has an effect on the hall voltage therefore the it is not accurately calibrated.

medusa said:
they give no current rating.
im sure without current no charge will flow.
but to calibrate it should constant current be passed through the probe?
like you could make a steady current of 1,2 or 3 amps to flow etc.
but this has an effect on the hall voltage therefore the it is not accurately calibrated.

I think others such as Chi Meson might be able to give you a better explanation here...

Zz.

someone help out

## 1. What is a Hall probe and how does it measure magnetic field strength?

A Hall probe is a small device that uses the Hall effect to measure the strength of a magnetic field. The Hall effect is the production of a voltage difference across an electrical conductor when it is placed in a magnetic field. The Hall probe uses this principle to measure the strength of the magnetic field by detecting the voltage difference and converting it into a numerical value.

## 2. What is the range of magnetic field strength that a Hall probe can measure?

The range of magnetic field strength that a Hall probe can measure depends on the sensitivity of the probe and the strength of the magnetic field. Most Hall probes have a range of several hundred milliTesla (mT) to a few Tesla (T), but some specialized probes can measure up to several hundred T.

## 3. What factors can affect the accuracy of a Hall probe measurement?

The accuracy of a Hall probe measurement can be affected by various factors, such as temperature, stray magnetic fields, and the orientation of the probe in relation to the magnetic field. To ensure accurate measurements, it is important to calibrate the probe regularly and minimize any external influences on the measurement.

## 4. Can Hall probes be used to measure magnetic fields in different materials?

Yes, Hall probes can be used to measure magnetic fields in various materials, including metals, semiconductors, and insulators. However, the sensitivity of the probe may vary depending on the material, and specialized probes may be needed for certain materials.

## 5. How can Hall probe measurements be used in scientific research and applications?

Hall probes are commonly used in scientific research and various applications, such as in the study of magnetism, material characterization, and non-destructive testing. They are also used in industries such as electronics, power generation, and medical imaging to measure and control magnetic fields.

• Introductory Physics Homework Help
Replies
9
Views
546
• Introductory Physics Homework Help
Replies
2
Views
1K
• Introductory Physics Homework Help
Replies
2
Views
3K
• Quantum Physics
Replies
0
Views
552
• Introductory Physics Homework Help
Replies
1
Views
1K
• Introductory Physics Homework Help
Replies
1
Views
4K
• Introductory Physics Homework Help
Replies
8
Views
939
• Electromagnetism
Replies
2
Views
1K
• Electromagnetism
Replies
7
Views
1K
• Introductory Physics Homework Help
Replies
7
Views
1K