Magnetic field measurement method and magnetic field measurement system
AssigneeHitachi, Ltd.
InventorHiroki Funato
Life of this patent
Estimating the term…
Abstract
To measure a magnetic field strength at each scan spacing s which is smaller than a loop size by scanning a magnetic field sensor (loop antenna) of the loop size. A magnetic field strength distribution is determined with spatial resolution of the spacing s along a scan direction, by performing arithmetic processing including addition and subtraction in relation to each of the measured magnetic field strength values. It is to be noted that the magnetic field sensor may be a magnetic field sensor array with plural magnetic field sensors placed at the spacing s.
Claims18
A magnetic field measurement method using a magnetic field sensor of a detection width L, the method comprising the steps of:
- scanning the magnetic field sensor in a direction of the detection width;
- measuring a magnetic field strength at each spacing s which is smaller than the detection width L;
- performing arithmetic processing including addition and subtraction in relation to the magnetic field strength values measured at the each spacing s;
- and
- determining the magnetic field strength at the detection width of the spacing s along a scanning direction.
A magnetic field measurement method using a magnetic field sensor of a detection width L, the method comprising the steps of:
- placing a plurality of magnetic field sensors at spacing s which is smaller than a detection width L in a direction of the detection width;
- measuring a magnetic field strength for each of the magnetic field sensors;
- performing arithmetic processing including addition and subtraction in relation to the magnetic field strength values measured for each of the magnetic field sensors;
- and
- determining the magnetic field strength at the detection width of the spacing s along a placement direction.
A magnetic field measurement method using a first magnetic field sensor and a second magnetic field sensor, wherein a portion of a detection area shape is different between them, the method comprising the steps of:
- measuring a magnetic field strength at a desired position by the first magnetic field sensor;
- measuring the magnetic field strength at the same position by the second magnetic field sensor;
- calculating a difference of the measured magnetic field strength values;
- and
- determining the magnetic field strength in an area in which the portion of the detection area shape is different between the first and second magnetic field sensors.
A magnetic field measurement system comprising:
- a magnetic field sensor of a detection width L for detecting the magnetic field;
- a control section for scanning the magnetic field sensor at spacing s which is smaller than the detection width L in a direction of the detection width;
- a measurement section for measuring a magnetic field strength at the each spacing s from a detection signal of the magnetic field sensor;
- and
- an arithmetic operation section for performing arithmetic processing including addition and subtraction in relation to the magnetic field strength values measured by the measurement section at the each spacing s,
- whereby to determine the magnetic field strength at the detection width of the spacing s along a scanning direction.
A magnetic field measurement system comprising:
- a magnetic field sensor array with a plurality of magnetic field sensors of a detection width L to detect magnetic fields placed at spacing s which is smaller than the detection width L in a direction of the detection width;
- a measurement section for measuring a magnetic field strength at the each spacing s from the magnetic field sensor array;
- and
- an arithmetic operation section for performing arithmetic processing including addition and subtraction in relation to the magnetic field strength values measured by the measurement section at the each spacing s,
- whereby to determine the magnetic field strength at the detection width of the spacing s along a placement direction.
Dependencies are inferred from the claim text.