The induction coil sensors (called also search coils, pickup coils or magnetic loop sensors) are described. The design methods of air coils and ferromagnetic core coils are compared and summarized. The frequency properties of the coil sensors are analyzed and various methods of output signal processing are presented. Special kinds of induction sensors, as Rogowski coil, gradiometer sensors, vib...

The measurement accuracy of a magnetic gradiometer relies on magnetometer consistency, accuracy, and assembly technology. traditional methods calibrate error, misalignment the interference field independently. However, after long time work, calibration parameters will inevitably change. Furthermore, it waste lot manpower material resources if is disassembled calibrated step by step. Given above...

We have defined new algorithms for the data processing of a satellite geodesy mission with gradiometer (such as the next European mission GOCE) to extract the information on the gravity field coefficients with a realistic estimate of their accuracy. The large scale data processing can be managed by a multistage decomposition. First the spacecraft position is determined, i.e., a kinematic method...

Multichannel superconducting quantum interference device (SQUID) systems based on double relaxation oscillation SQUIDs (DROS) were developed for measuring magnetocardiography (MCG) and magnetoencephalography (MEG) signals. Since DROS provides large fluxto-voltage transfer coefficients, about 10 times larger than the DC SQUIDs, direct readout of the SQUID output was possible using compact roomte...

We report measurements of spectroscopic linewidth and Rabi oscillations in three thin-film dc SQUID phase qubits. One device had a 6-turn Nb loop, the second had a single-turn Al loop, and the third was a first order gradiometer formed from 6-turn wound and counter-wound Nb coils to provide isolation from spatially uniform flux noise. In the 6 7.2 GHz range, the spectroscopic coherence times fo...

Gradiometer resembles in functionality a magnetic field sensor where it measures the magnetic field gradient and its sensitivity is determined by the ability to quantify differential voltage change with respect to a reference value. Magnetoelectric (ME) gradiometer designed in this study is based upon the nickel (Ni)-Pb(Zr,Ti)O(3) (PZT) composites and utilizes the ring-dot piezoelectric transfo...

This paper describes the use of two simple electromagnetic methods for detecting strut fractures in prosthetic heart valves. The first method involves immersing the heart valve in a uniform time varying electromagnetic field and measuring the perturbation of the field in regions proximate to the strut. In vitro tests done to date indicate that the method is capable of discriminating between int...