Patent ID: 9128009
Filing Date: 2015-09-08
Classification: G01N

Abstract:
1. A change in elastic modulus (ΔE) measuring device minimizing external magnetic disturbance, comprising: three-axis Helmholtz coils arranged in x, y, and z axis directions to remove the earth's magnetic field; a three-axis magnetic sensor installed at the center of the three-axis Helmholtz coils to measure magnetic fields formed in the three-axis Helmholtz coils; a second power supply unit supplying offset current offsetting the measured magnetic fields to the three-axis Helmholtz coils according to the measured magnetic fields; a variable direct current (DC) magnetic field applying coil inserted into and seated in the three-axis Helmholtz coils; a frequency variable alternate current (AC) magnetic field applying coil inserted into and seated in the variable DC magnetic field applying coil; a magneto acoustic resonance signal detecting coil inserted into and seated in the frequency variable AC magnetic field applying coil and having a sample inserted thereinto and seated therein, the sample corresponding to an object to be measured; a signal generator applying an AC current signal to the frequency variable AC magnetic field applying coil; a first power supply unit applying a DC current signal to the variable DC magnetic field applying coil; a signal measuring unit measuring a magneto acoustic resonance frequency detected in the magneto acoustic resonance signal detecting coil; and a calculating unit calculating an elastic modulus using the magneto acoustic resonance frequency and commanding the second power supply unit to supply the offset current.