Disclosed herein is an electric pot having an improved relay installation position. The electric pot includes a pot main body that is provided with a magnetic field generator generating a magnetic field at a lower portion of the pot main body, and a supporter that includes a magnetism detection sensor detecting magnitude of a magnetic field generated by the magnetic field generator and, based on the detected magnitude of a magnetic field, generating a voltage and that includes a comparator comparing the voltage generated by the magnetism detection sensor with a predetermined reference voltage and, based on the comparison, controlling a switchover operation of a relay part, thereby controlling the relay part through a simple circuit configuration and through magnetic field generation and detection means without an additional communication means.

An apparatus for determining magnetic properties of a portion of a magnetizable endless belt. The apparatus includes a primary coil for generating a magnetic field. The windings of the primary coil are wound around the endless belt. A secondary coil measures the magnetic flux density. A slotted yoke guides the magnetic flux. The endless belt extends through slots in the yoke. First measuring devices measure the magnetic field in a width portion parallel to the endless belt. Second measuring devices measure the magnetic field in the width portion parallel to the endless belt.

An exemplary method of indicating a condition of grout within a post-tensioned tendon involves positioning a magnet and a metallic sensing plate in close proximity to an outer surface of the post-tensioned tendon; rotating the magnet and the metallic sensing plate around the outer surface of the post-tensioned tendon; measuring an amount of magnetic forces applied to the magnet during rotation of the magnet around the post-tensioned tendon; measuring an impedance between the metallic sensing plate and metallic strands within the post-tensioned tendon during rotation of the metallic sensing plate around the post-tensioned tendon; and generating an image of a cross-section of the post-tensioned tendon indicating one or more grout conditions in spatial proximity to the metallic strands within the post-tensioned tendon based on measurement data using the magnet and the metallic sensing plate.

A system and method that can automatically select a frequency of a magnetic field in a magnetic tracking system. A magnetic tracking system emits an alternating magnetic field using a set of three frequencies. In the present approach, a transmitter is capable of generating multiple sets of three frequencies. A processor selects a first set of frequencies to use and causes the receiver to measure the amplitude of the magnetic field at those frequencies. In one embodiment, the frequency set having the lowest energy is selected. The processor then compares an estimated jitter at those frequencies to the actual jitter experienced using the frequencies. If the actual jitter exceeds the estimated jitter by a predetermined amount, the processor switches to a different set of frequencies and causes the receiver to measure the magnetic field at the new set of frequencies. The process may repeat using the additional sets of frequencies.

A solenoid device for generating or detecting electrical or magnetic fields includes at least two solenoids combined into a solenoid structure. A two level solenoid structure is formed by helically wrapping a long and bendable primary solenoid around a secondary core to create a secondary solenoid which includes the primary solenoid as a part. If the secondary solenoid is bendable and long enough, it can be helically wrapped around a tertiary core to form a tertiary solenoid which contains the primary solenoid and the secondary solenoid as parts. The upper level solenoid will generally contain a hollow core into which items or bodies to be treated with electrical or magnetic fields can be inserted for treatment. Further, items having inherent magnetic or electrical fields or properties can be inserted into the hollow core so the inherent fields can be detected.

An electromagnetic gradiometer that includes multiple torsionally operated MEMS-based magnetic and/or electric field sensors with control electronics configured to provide magnetic and/or electric field gradient measurements. In one example a magnetic gradiometer includes a first torsionally operated MEMS magnetic sensor having a capacitive read-out configured to provide a first measurement of a received magnetic field, a second torsionally operated MEMS magnetic sensor coupled to the first torsionally operated MEMS magnetic sensor and having the capacitive read-out configured to provide a second measurement of the received magnetic field, and control electronics coupled to the first and second torsionally operated MEMS magnetic sensors and configured to determine a magnetic field gradient of the received magnetic field based the first and second measurements from the first and second torsionally operated MEMS electromagnetic sensors.

A method for calibrating a sensor system, including: providing at least one first sensor unit and one second sensor unit, providing first correction data for the first sensor unit on the basis of measuring signals of the first sensor unit, providing second correction data for the first sensor unit, in the case of an activated second sensor unit, on the basis of measuring signals of the first sensor unit and on the basis of measuring signals of the second sensor unit, determining a first quality parameter for the first correction data and a second quality parameter for the second correction data, determining present correction data for measuring signals of the first sensor unit based on the correction data having the highest of the two determined quality parameters, and calibrating the first sensor unit by correcting first measuring signals on the basis of the present correction data.

A method is disclosed. In one example, the method includes bonding a first panel of a first material to a base panel in a first gas atmosphere, wherein multiple hermetically sealed first cavities encapsulating gas of the first gas atmosphere are formed between the first panel and the base panel. The method further includes bonding a second panel of a second material to at least one of the base panel and the first panel, wherein multiple second cavities are formed between the second panel and the at least one of the base panel and the first panel.

A valve position sensor is described. The valve position sensor includes a sensor housing for placement on a moving component of a valve. A print circuit board assembly is disposed within the housing. The print circuit board assembly includes one or more micro sensors that includes a magnetometer and a gyroscope. A processing unit performs a calibration routine that associates magnetometer data received from the magnetometer with valve position data received from the gyroscope. The processing unit receives data from the magnetometer and compares the received magnetometer data with the calibration data to determine valve position data relating to an estimate of the valve position. A transmitter wirelessly transmits event data including valve position data to an external receiver.

A method for measuring a magnetic field with a micro-sensor system includes applying a direct current (I.sub.Th) to a curved micro-beam to control a stiffness of the curved micro-beam; placing the micro-sensor system into an external magnetic field (B); selecting with a controller, based on an expected value of the external magnetic field (B), a given resonant frequency of the micro-beam; measuring with a resonant frequency tracking device the given resonant frequency of the micro-beam; and calculating in the controller the external magnetic field (B), based on (1) the measured resonant frequency, (2) the applied current (I.sub.Th), and (3) calibration data stored in the controller. The calibration data is indicative of a dependency between a change of the selected resonant frequency and the external magnetic field.