A method and apparatus for measuring multiple parameters of drilling fluid using electric field perturbation, permittivity curves, time domain analysis and frequency domain analysis to identify constituents of drilling fluid and ratios of the drilling fluid constituents on a real time basis and to measure volumes and densities of the constituents on a real time basis.

An apparatus includes a near-field probe having loops or coils of electrically-conductive material, where the near-field probe is configured to generate a magnetic field. The apparatus also includes a power amplifier configured to drive the near-field probe. The apparatus further includes a shunt capacitance coupled in parallel across the loops or coils of the near-field probe. The shunt capacitance and an inductance of the loops or coils of the near-field probe form part of a resistive-inductive-capacitive (RLC) network. The RLC network is configured to transform a smaller resistance of the near-field probe into a larger resistance. In some cases, the apparatus may include multiple near-field probes coupled in series, and the power amplifier may be configured to drive the multiple near-field probes. For each near-field probe, the apparatus may include a shunt capacitance coupled in parallel across the loops or coils of the near-field probe.

A fast calibration method for slide-screw impedance tuners employs a new tuner control board and routine with independent direct triggering and data sampling by the VNA; a new vertical scaling algorithm bypasses the traditional iterative approach and uses numerical curve-fitting and ISO circle definition. Full tuner calibration executes without motor stopping, yielding time reduction typically by a factor of 8.

A probe card for measuring micro-capacitance comprises a substrate and a capacitance-to-digital converter. The substrate has a first surface and a second surface. A plurality of conductive contacts is disposed on the first surface. A plurality of probes is disposed on the second surface. The probes are electrically connected with the corresponding conductive contacts. The capacitance-to-digital converter is disposed on the first surface and electrically connected with the corresponding conductive contacts to measure at least one micro-capacitance of an analyte and convert the micro-capacitance into a digital signal. The abovementioned probe card has an advantage of low cost.

Various examples are provided related to anisotropic constitutive parameters (ACPs) that can be used to launch Zenneck surface waves. In one example, among others, an ACP system includes an array of ACP elements distributed over a medium such as, e.g., a terrestrial medium. The array of ACP elements can include one or more horizontal layers of radial resistive artificial anisotropic dielectric (RRAAD) elements positioned in one or more orientations over the terrestrial medium. The ACP system can include vertical lossless artificial anisotropic dielectric (VLAAD) elements distributed over the terrestrial medium in a third orientation perpendicular to the horizontal layer or layers. The ACP system can also include horizontal artificial anisotropic magnetic permeability (HAAMP) elements distributed over the terrestrial medium. The array of ACP elements can be distributed about a launching structure, which can excite the ACP system with an electromagnetic field to launch a Zenneck surface wave.

An in-situ evaluation method and system for loess collapsibility based on non-destructive time-domain reflection technology, includes: calculating loess dry density and mass water content; considering loess dry density, mass water content and basic physical property indicators, and evaluating loess collapsibility in situ through mathematical models. The loess collapsibility in-situ evaluation method based on the non-destructive time domain reflectometry technology of the present invention can not only realize whether the loess has collapsibility, but also has the potential to distinguish strong, medium and slight collapsibility.

Disclosed is a TDR measuring apparatus for determining the dielectric constant and material properties derived therefrom of a medium flowing through a pipeline. The apparatus includes signal generation electronics which generate TDR measurement signals, transmitting and receiving electronics, a coupling-in/coupling-out apparatus which couples the TDR measurement signals into and out of an electrically conductive measuring probe of a predefined length, and control/evaluation electronics which use the propagation time of the TDR measurement signals to determine the dielectric constant. The measuring probe is arranged in an electrically insulated manner outside of the pipeline. Alternately, the measuring probe is placed in the pipeline such that the outer surface of the measuring probe facing the medium terminates flush with the inner surface of the pipeline and is configured such that the propagation time and the amplitude of the measurement signals on the measuring probe are dependent on the dielectric constant of the medium.

Various examples are provided related to anisotropic constitutive parameters (ACPs) that can be used to launch Zenneck surface waves. In one example, among others, an ACP system includes an array of ACP elements distributed above a medium such as, e.g., a terrestrial medium. The array of ACP elements can include one or more horizontal layers of radial resistive artificial anisotropic dielectric (RRAAD) elements positioned in one or more orientations above the terrestrial medium. The ACP system can include vertical lossless artificial anisotropic dielectric (VLAAD) elements distributed above the terrestrial medium in a third orientation perpendicular to the horizontal layer or layers. The ACP system can also include horizontal artificial anisotropic magnetic permeability (HAAMP) elements distributed above the terrestrial medium. The array of ACP elements can be distributed about a launching structure, which can be excited with an electromagnetic field to facilitate the launch of a Zenneck surface wave.

Various examples are provided related to anisotropic constitutive parameters (ACPs) that can be used to launch Zenneck surface waves. In one example, among others, an ACP system includes an array of ACP elements distributed above a medium such as, e.g., a terrestrial medium. The array of ACP elements can include one or more horizontal layers of radial resistive artificial anisotropic dielectric (RRAAD) elements positioned in one or more orientations above the terrestrial medium. The ACP system can include vertical lossless artificial anisotropic dielectric (VLAAD) elements distributed above the terrestrial medium in a third orientation perpendicular to the horizontal layer or layers. The ACP system can also include horizontal artificial anisotropic magnetic permeability (HAAMP) elements distributed above the terrestrial medium. The array of ACP elements can be distributed about a launching structure, which can be excited with an electromagnetic field to facilitate the launch of a Zenneck surface wave.

An apparatus includes a near-field probe having loops or coils of electrically-conductive material, where the near-field probe is configured to generate a magnetic field. The apparatus also includes a power amplifier configured to drive the near-field probe. The apparatus further includes a shunt capacitance coupled in parallel across the loops or coils of the near-field probe. The shunt capacitance and an inductance of the loops or coils of the near-field probe form part of a resistive-inductive-capacitive (RLC) network. The RLC network is configured to transform a smaller resistance of the near-field probe into a larger resistance. In some cases, the apparatus may include multiple near-field probes coupled in series, and the power amplifier may be configured to drive the multiple near-field probes. For each near-field probe, the apparatus may include a shunt capacitance coupled in parallel across the loops or coils of the near-field probe.