Magnetic Field Sensor basics
This page covers Magnetic Field Sensor basics and mention Magnetic Field Sensor types. Induction Coil,FluxGate,SQUID,Hall Effect,Magnetoresistance,Proton Precession and Optically pumped are popular magnetic field sensors. The page provides links to other sensors used for various applications.
The basic ourpose of magnetic field sensor is to measure magnetic field strength. It can be measured in units of A/m or Tesla or Gauss.
Based on the magnetic field strength measurement need appropriate sensor is choosen. These sensors are used in the manufacturing of magnetic field meters or EMF meters.
Magnetic Field Sensor types
Magnetic field sensors are categorized into vector and scalar types. The vector type of magnetic sensors are further divided into low field measurement sensors and high field measurement sensors.
The instruments which employ low field sensors are known as magnetometers. These magnetometers measure fields less than 1 mT. the instruments which employ high field sensors are known as gaussmeters. The gaussmeters measure fields greater than 1 mT.
The Vector type of magnetic field sensors are as follows. These are
used in magnetometers.
• Search Coil
• Fluxgate
• SQUID
• Magneto-resistive
• Fiber Optic
The scalar type of magnetic field sensors are as follows.
These are also used in magnetometers.
• Proton Precession
• Optically Pumped
The magnetic field sensors used in gaussmeters are as follows.
• Hall Effect
• Magneto-resistive
• Magneto-diode
• Magneto-transistor
These divisions are based on field strength range, resolution and bandwidth. Based on these data, sensors are used in field strength measurement instruments.
Sensor type | Range (mT) | Resolution (nT) | Bandwidth (Hz) | Description |
---|---|---|---|---|
Induction Coil | 10-10 to 106 | Variable | 10-1 to 106 | Can not be used to measure static field type |
FluxGate | 10-4 to 0.5 | 0.1 | DC to 2 x 103 | used in general purpose vector type of magnetometer |
SQUID | 10-9 to 0.1 | 10-4 | DC to 5 | Magnetometer with higher sensitivity |
Hall Effect | 0.1 to 3 x 104 | 100 | DC to 108 | Best to be used for fields greater than 1 tesla |
Magnetoresistance | 10-3 to 5 | 10 | DC to 107 | It is good to use it for mid-range applications |
Proton Precession | 0.02 to 0.1 | 0.05 | DC to 2 | Scalar magnetometer for general purpose use |
Optically pumped | 0.01 to 0.1 | 0.005 | DC to 5 | Scalar magnetometer for high resolution need |
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