Gauss measures magnetic field strength otherwise known as flux density, usually at a particular point. The Gauss was an integral part of the centimeter-gram-second (cgs) system of units. It was however replaced by the tesla (T) in the modern SI (International System) of Units.
You can express magnetic field strength in other units other than Gauss given the following relationships:
1 Gauss (G) = 1 Mx/cm²
1 Gauss (G) = 10-4 Tesla (T)
1 Gauss (G) = 103 milliGauss (mG)
1 Gauss (G) = 104 microGauss (µG)
1 Gauss (G) = 106 nanoGauss (nG)
1 Gauss (G) = 10-2 oersted (Oe)
Factors Influencing Gauss Value
Various factors can influence the Gauss value within a magnetic field or a given location. Understanding these factors allows you to appropriately interpret and manipulate magnetic field strength for various applications.
i. Current Flow: For electromagnets in a circuit with current flow, the Gauss value depends on the strength of the conductor current. The higher the conducted current, the stronger the magnetic field.
ii. Distance from the Source: Magnetic field strength is seen to reduce inversely proportional to the distance square. Therefore, if you double the distance from a magnets source, the result will be a reduction in Gauss value. Usually, the value reduces to about a 4th of the original strength.
iii. Material: The magnetic field strength will vary depending on the type of magnetic materials.
iv. Interference: When external field affect the magnetic field, you will notice a deviation in the Gauss value.
v. Magnetic Source: When there is stronger magnetic source, expect the Gauss values to be higher.
vi. Environmental Factors: Certain environmental variables such as pressure and temperature may affect the magnetic properties. As a result, you should expect the Gauss value to change.
vii. Hysteresis: Hysteresis will affect Ferromagnetic materials. Consequently, you will see a change in the Gauss readings.
Importance of Gauss Measurement
There are many ways you can use these values in the modern applications:
i. Tracking magnetic field whether from the background, or source that can cause electromagnetic interference.
ii. Determining intensity of a magnetic field from electronic equipment.
iii. They help when studying earth’s magnetic field.
iv. You can assess the strength of different magnetic materials.
v. Gauss measurements are used by MRI machines to control the intensity of magnetic fields produced during imaging procedures.
vi. When designing magnetic shielding for use against external magnetic fields, Gauss measurements help assess their effectiveness.
Notable Gauss Values
Gauss values vary widely with the following notable values:
- A basic refrigerator magnets Gauss value is 50G while an iron magnet measures 100G.
- An MRI machine used for medical imaging may have magnetic field strengths between 3000–70000 G.
- Iron alloys used in transformers have a high permeability saturation ranging between 16000 to 22000G.
- The Earth’s magnetic field strength at its surface typically ranges between 0.25–0.60 G depending on the location and geological factors.
- The Large Hadron Collider operates with magnetic fields of up to 83,300 Gauss.
- The remanence of neodymium magnets can range from 10,000G to over 20,000 Gauss.
Gauss Vs Tesla
Both Gauss and Tesla are units of measuring magnetic field strength with the latter replacing the former as the SI unit. Gauss can be represented as Maxwell per square centimeter whereas Tesla as Newton per ampere meter.
When it comes to international system of units, Tesla is the standard unit for measuring magnetic field strength rather than Gauss. As it is a larger unit compared to Gauss, it is more practical in describing and measuring magnetic fields over a wide application range.
How Do You Measure Gauss Strength
Different instruments are capable of measuring Gauss strength. The measurement method is dependent on magnetic field strength and frequency and also the application. Interference sources can affect accuracy in measuring Gauss strength and the measuring instrument’s sensitivity should therefore be considered.
Some of the common methods used in measuring Gauss strength include:
i. Hall Effect Sensors: These are silicon devices that can measure the strength of a magnetic field by producing a voltage proportional to the field strength.
ii. Magnetometers: These instruments are specifically designed for measuring magnetic fields with various types available featuring different measurement range and sensitivity.
iii. Hall Probe: Is a specialized sensor highly sensitive to magnetic fields providing an efficient way to measure magnetic field strength.
iv. Superconducting Quantum Interference Devices: As very sensitive detectors, SQUIDs are used to measure very weak magnetic fields.
Other than just strength, a Gauss meter also measures magnetic field direction. It finds use in applications such as assessing electromagnetic interference, testing magnets, mapping magnetic fields and analyzing magnetic materials.
A summary of a Gauss meter’s primary features and functions is as follows:
- Gauss meters provide accurate measurements of magnetic field strength in units of Gauss (G) or Tesla (T).
- Capable of providing a range of magnetic fields from weak to strong based on their obtained values.
- A sensor enables the Gauss meter to detect magnetic field presence.
- A display on the Gauss meter shows the obtained magnetic field intensity reading.
- The Gauss meter can detect slight changes in the strength of a magnetic field during measurement.
While facing diminished use in modern times, the Gauss still offers a reliable way of measuring especially low magnetic field strengths. An understanding of gauss can also help you correctly interpret older literature when doing research.