User:Magnetic models/sandbox

Method of testing the magnetoelastic properties of soft magnetic materials
Method suitable for effective testing of magnetoelastic effect in magnetic materials should fulfil following requirements :
 * magnetic circuit of tested sample should be closed. Open magnetic circuit causes demagnetization, what reduce magnetoelastic effect and complicate its analyse.
 * distribution of stresses should be uniform. Value and direction of stresses should be known.
 * there should be the possibility of winding of the sample by magnetizing and sensing windings - necessary to measure magnetic hysteresis loop under mechanical stresses.

Following methods of testing the magnetoelastic properties of magnetic materials were developed:
 * tensile stresses applied to the strip of magnetic material in the shape of ribbon . Disadvantage: open magnetic circuit of the tested sample.
 * tensile and compressive stresses applied to frame sample . Disadvantage: only bulk materials may be tested. No stresses in the joints of columns.
 * compressive stresses applied to the ring core in direction of diameter . Disadvantage: non-uniform stresses in the core.
 * tensile and compressive stresses applied to the ring sample perpendicularly to its base . Disadvantage: stresses are perpendicular to magnetizing field.

Applications of magnetoelastic effect
Magnetoelastic effect can be used in development of force sensors. This effect was used for sensors:
 * in civil engineering.
 * for monitoring of large diesel engines in locomotives.
 * for monitoring of ball valves.
 * for biomedical monitoring.

Magnetoelastic effect have to be also considered as side effect of accidental application of mechanical stresses to the magnetic core of inductive component, e.g. fluxgates.

Magnetovision is the measuring technique enabling visualization of magnetic field distribution in given space.

Magnetovision measuring setup
Magnetovision measuring stand consists magnetometer, X-Y or X-Y-Z movement mechanism and data processing and visualization system. Following modes of acquisition of magnetovision signal are possible:


 * magnetometer moves in measuring area (e.g. over tested object)
 * tested object moves against magnetometer
 * array of magnetic field sensors is used

Magnetometers for magnetovision
Typically for magnetoviosion following types of sensors may be used:


 * magnetoresistance effect based sensors
 * fluxgate magnetometers
 * Hall effect sensors
 * SQUIDs

Types of magnetovision
There are different modes of magnetovision measurements. Measurements may be performed in 2D (X-Y) or 3D (X-Y-Z). Moreover, measurements of magnetic field may be absolute or differential.

Applications of magnetovision
Magnetoviosion may be used for:


 * nondestructive testing in civil engineering
 * detection of dangerous metallic objects
 * archeology

Data fusion in magnetovision
Magnetovision images may be used for data fusion with visual signal. This creates new possibility of presentation of magnetic field distribution for further analyses.