A method of impedance measurement of a device under test (DUT) is disclosed based on a random excitation signal, the method comprising the steps of generating the random excitation signal, applying the generated random excitation signal to the DUT through two points of a data acquisition board (DAQ) and re-structuring the converted random excitation signal through a plurality of iterative calibration loops, wherein spectral phase of the random excitation signal is derived from a discrete uniform distribution and its time domain amplitude is controllable. The random excitation signal is a structured Gaussian White Noise (GWN) signal or sequence, which is generated based on the user-defined input parameters such as white noise power level, frequency range between the minimum and maximum frequencies (F.sub.min and F.sub.max), and frequency step (F.sub.step).

Methods for determining variability in a state of a medium, include monitoring the medium and determining the variability in the state of the medium based on the processing of the response over time based on the response detected at the at least one receive element over time. Monitoring the medium can include generating a transmit signal, transmitting it into the medium using a transmit element, and receiving a signal from the medium at a receive element. The transmit and receive elements can be decoupled from one another. The transmit and receive elements can have differing geometry. The determined variability in the state of the medium can be used to provide notifications and/or take automated actions.

This invention relates to a pipeline-inspecting device. More specifically, the invention relates to a pipeline-inspecting device capable of at least (i) detecting defects in the lining of the pipeline; (ii) visually marking each of the defects in the pipeline; and (iii) recording the location of each of the defects along such pipeline in a single pass. The pipeline-inspecting device includes a primary body (20) being operably movable along a pipeline, fitted with a plurality of primary contacts (40) extending radially from the primary body (20) for operably riding in contact with an internal surface of the pipeline, the contacts (40) being spaced circumferentially relative to one another through 360 degrees about the primary body (20). The device further includes one or more secondary contacts (116) for operably connecting the device to the pipeline and a plurality of marking members (66) associated with each of the respective contacts (40) for visually marking the internal surface of the pipeline in the vicinity of defects detected therein, wherein the defects are operably detected by monitoring an electrical condition change between the primary (40) and secondary contacts (116). In use, and in the event of an electrical condition change arising between one of the primary contacts (40) and the secondary contact (116), the marking member associated with that respective primary contact (40) marks the internal surface of the pipeline in the vicinity of the defect detected by such primary contact (40).

Various implementations include systems and approaches for measuring an electromagnetic impedance characteristic of a fluid under test (FUT) in a fluid channel. In some cases, a system includes: a transmitting electrode assembly including: a transmitting electrode having a transmitting surface; and a transmitting electrode backer ground plate at least partially surrounding the transmitting electrode; a receiving electrode assembly including: a receiving electrode having a receiving surface; and a receiving electrode backer ground plate at least partially surrounding the receiving electrode, where the transmitting electrode and the receiving electrode are located in a set of walls defining the fluid channel, the transmitting surface and the receiving surface each conform to a shape of the set of walls defining the fluid channel, where the fluid channel permits transverse flow of the FUT relative to both the transmitting electrode and the receiving electrode.

An apparatus for non-destructive testing of a sample includes a sample holder configured to contain or support the sample; an exciter configured to generate an oscillating electromagnetic field across the sample that operates with at least one predetermined excitation frequency; a receiver configured to detect harmonic electromagnetic signals resulting from induced electromagnetic fields oscillating with at least one frequency that is not equal to the at least one predetermined excitation frequency; a recorder configured to record the harmonic electromagnetic signals; and a processor programmed to construct an induced harmonic electromagnetic spectrum based on the harmonic electromagnetic signals.

A system and method for measuring resistance over an array. The array includes at least three electrodes. Nodes at each intersection between input electrodes and output electrodes have variable resistance. A driving voltage is applied to a selected input electrode and an output current is received at a selected output electrode. A selected node is at the intersection of the two selected electrodes and includes an electrical component with a resistive property. Remaining electrodes are connected with a ground for isolating the selected node from the effects of changes in impedance of the remaining nodes. The driving voltage is converted to an output current by resistance at the selected node. The output current is converted to an output voltage with a current-to-voltage converter circuit for measuring the resistance of the electrical component. The nodes may be measured as the selected node in sequential or non-sequential patterns.

A system and method for measuring resistance over an array. The array includes at least three electrodes. Nodes at each intersection between input electrodes and output electrodes have variable resistance. A driving voltage is applied to a selected input electrode and an output current is received at a selected output electrode. A selected node is at the intersection of the two selected electrodes and includes an electrical component with a resistive property. Remaining electrodes are connected with a ground for isolating the selected node from the effects of changes in impedance of the remaining nodes. The driving voltage is converted to an output current by resistance at the selected node. The output current is converted to an output voltage with a current-to-voltage converter circuit for measuring the resistance of the electrical component. The nodes may be measured as the selected node in sequential or non-sequential patterns.

A measurement device with improved electrical strength comprises an input for receiving an input signal as well as a measurement circuit connected with the input. The measurement circuit has at least one component. The measurement device also comprises an electrical interface provided in addition to the input. The measurement device further comprises at least one internal enclosure that encloses the component within the measurement device, thereby improving the electrical strength of the measurement device.

A measurement device with improved electrical strength comprises an input for receiving an input signal as well as a measurement circuit connected with the input. The measurement circuit has at least one component. The measurement device also comprises an electrical interface provided in addition to the input. The measurement device further comprises at least one internal enclosure that encloses the component within the measurement device, thereby improving the electrical strength of the measurement device.

A method for measuring performance of at least one DUT in a reverberation chamber over a frequency band, the method including, iteratively: generating a fading scenario by the reverberation chamber; identifying at least one measurement sub-band included in the frequency band, wherein the at least one measurement sub-band complies with a gain flatness criterion; measuring performance of the at least one DUT in the at least one identified measurement sub-band, thereby generating at least one performance measurement result; accumulating the at least one performance measurement result; and determining measurement coverage and terminating the performance measurement in case the measurement coverage meets a coverage criterion.