478results about "Fluid resistance measurements" patented technology

A conductivity detector detects the electrical conductivity of a fluid under analysis for determining chemical or physical properties of the fluid that are related its electrical properties. Such conductivity detectors may find use in, for example, hemodialysis systems for analyzing the effectiveness of the hemodialysis treatment. In an aspect, to improve accuracy of the conductivity measurements, the detector utilizes four-wire resistance measurement methods. In another aspect, to avoid fouling or contamination of the electrodes, the detector utilizes capacitively-coupled contactless conductivity detection (C4D) methods so that the electrodes are physically unconnected to the fluid contained in a fluid chamber. In a possible further aspect, the fluid chamber may be a disposable component removable from the electrodes. The conductivity detector can include other features such as calibration circuits and features for electrically isolating the fluid under detection from the fluid in the rest of the system.

A sensor, a system of direct measurement using that sensor, and a method of direct and simultaneous measurement of conductivity and dielectric constant of a fluid, particularly high impedance, hydrocarbon-based fluids. The sensor has a cell that holds the fluids to be measured between a single pair of coaxial, bare metal electrodes connected through interface circuitry to measurement circuitry preferably implemented in one or several IC's. The sensor has a mutually compatible electrode geometry that provides both the correct cell constant for measurement of conductivity of hydrocarbons fluids (typical range 0-100,000 pS/cm), and a bulk capacitance (for use in dielectric constant measurement) in the range of measure of readily available low cost commercial IC's (having a typical capacitance measurement span of <10 pF, with a total bulk capacitance at the chip of <20 pF). The cell conductivity constant for use with hydrocarbon-based oils having a conductivity in the range of 1 to 500,000 pS/M is preferably less than or equal to about 0.1. The cell bulk capacitance with hydrocarbon fluids inside the sensor results in a bulk capacitance of at least about 4 pF. In one embodiment, the electronic circuitry is a Microcontroller/DSP that both generates synchronous drive signals at various frequencies, for both conductivity and dielectric constant measurements while directly digitizing and numerically processing the sensor output.

A multi-sensor as disclosed herein can include a substrate and at least three sensing elements disposed on the substrate. Each sensing element includes two electrodes separated by a distance and a nanowire mat adjacent to and in contact with the electrodes. The nanowire mats include nanowires which define a percolation network. The density of the nanowires in the nanowire mat of one sensing element is different than the density of the nanowires in the nanowire mat of either of the other at least two sensing elements.

The present invention is directed toward oxidation-resistant, ligand-capped nanoparticles, each comprising one or more capping ligands on a copper-containing core. Methods of making and using these nanoparticles are also disclosed.

Methods and systems for improving the sensitivity of a variety of conductivity sensing devices, in particular capacitively-coupled contactless conductivity detectors. A parallel inductor is added to the conductivity sensor. The sensor with the parallel inductor is operated at a resonant frequency of the equivalent circuit model. At the resonant frequency, parasitic capacitances that are either in series or in parallel with the conductance (and possibly a series resistance) is substantially removed from the equivalent circuit, leaving a purely resistive impedance. An appreciably higher sensor sensitivity results. Experimental verification shows that sensitivity improvements of the order of 10,000-fold are possible. Examples of detecting particulates with high precision by application of the apparatus and methods of operation are described.

A logging-while-drilling tool is adapted for incorporation with a drill string having a longitudinal axis. The drill string is further adapted for drilling a wellbore penetrating a geological formation. The drilling tool includes a tool body having a central axis disposed in parallel relation with the longitudinal axis of the drill string and an external, circumferential surface spaced radially outward from the central axis. The tool also includes a measurement apparatus for measuring resistivity of a borehole fluid in the wellbore. The measurement apparatus has an electrode array including a current emitting electrode disposed on the circumferential surface. The current emitting electrode is adapted to emit current into a target region of the wellbore spaced laterally between the circumferential surface and the walls of the wellbore. Further, a current receiving electrode is disposed on the circumferential surface and spaced apart from the current emitting electrode. The current receiving electrode is adapted to receive current propagated from the current emitting electrode into the target region. The electrode array occupies an arcuate section of the circumferential surface that extends less than about 180° about the central axis.

A method is disclosed for downhole determination of the resistivity of fluids from formations surrounding an earth borehole, including the following steps: providing a formation testing logging device that includes a coil and a flow line passing axially through the coil; determining a reference quality factor of the coil; positioning the formation testing device in the borehole, and causing formation fluid to flow through the flow line; measuring the quality factor of the coil with formation fluid in the flow line; and determining the resistivity of the formation fluid in the flow line as a function of the measured quality factor and the reference quality factor.

A method for investigating a target environment to determine whether or in what amount a chemical species may be present therein, which comprises: (a) exposing to said environment an article of manufacture comprising a multiplicity of particles in close-packed orientation, said particles having a core of conductive metal or conductive metal alloy and deposited thereon a ligand which is capable of interacting with said species such that a property of said multiplicity of particles is altered; (b) subjecting said multiplicity of particles to conditions sufficient for said property to be exhibited; and (c) monitoring said property to determine whether there is, or the amount of, any change as an indication of whether, or in what amount, said species is present; a multiplicity of particles suitable for use in such method; and equipment suitable for implementing the method.

A method of noncontact measuring the electrical conductivity of electrolytes using a primary measuring transformer includes placing the electrolyte in a sampler, exciting an alternating magnetic field using an axisymmetrical eddy current sensor, switching to the sensor a capacitor of variable capacitance, tuning of the formed circuit in resonance with the frequency of the generator of harmonic oscillations, and recording the change in the introduced active resistance of the parametric eddy current sensor rated against its own inductive resistance.

The invention discloses a capacitor coupling noncontact conductance measurement device and method. The device comprises an alternating-current excitation source, an insulated measurement pipeline, an excitation electrode, a detection electrode, a range resistor, a virtual inductor, a differential amplifier module and a signal processing module, wherein one end of the virtual inductor is connected with the range resistor, while the other end is grounded, meanwhile, two ends of the range resistor are connected with the differential amplifier module. The virtual inductor substitutes an actual inductor, thus effectively overcoming the adverse effect of a coupled capacitor on the measurement result according to the series resonance principle. The virtual inductor is a grounding inductor, and compared with a floating inductor, the virtual inductor is good in working stability and simple in circuit structure; compared with an actual inductor, the virtual inductor capable of adjusting the equivalent inductance value reduces the requirement for the frequency of the excitation source. In addition, different from a noncontact conductance measurement method adopting a current method, the capacitor coupling noncontact conductance measurement method adopts a voltage method to obtain the equivalent conductance value of measured conductive fluid, thus providing helpful reference for solving the conductance measurement problem of conductive fluid in a pipeline.

An apparatus for measuring fluid resistivity includes a flow line adapted to be in fluid communication with formation fluids, wherein the flow line includes a first section comprising a first conductive area, a second section comprising a second conductive area, and an insulating section disposed between the first section and the second section to prevent direct electrical communication between the first section and the second section; a first toroid and a second toroid surrounding the flow line around the first section and the second section, respectively, wherein the first toroid is configured to induce an electrical current in a fluid in the flow line and the second toroid is configured to measure the electrical current induced in the fluid in the flow line; and an electronic package to control functions of the first toroid and the second toroid.

This invention relates to a measurement method for solution conductivity, which applies an AC signal source with a semi-cycle pulse width of t to the two poles of a conduction tank to compute the conductivity or resistivity by testing the value of a X< 1 > signal of the tank at T< X1 > in the sphere of any semi-cycle 0-49%t and the value of X< 2 > at T< X2 > in the sphere of any semi-cycle 51-100% t. In this invention, when the value of X< 1 >/X< 2 > is greater than a pre-designed upper limit value or the value of X< 2 >/X< 1 > is smaller than a pre-designed lower limit, it puts forward test alarms to ask for exchanging the conduction poles of even larger conduction tank constant for even stable test to avoid measurement with greater errors.

Low power corrosion measurement devices are described with improved LPR, HDA, and ECN measurement capabilities in a field transmitter for online corrosion monitoring or off-line corrosion data logging.

The present invention provides an apparatus and method for measuring the conductivity of a fluid employing the differential radio frequency phase detection between two embedded toroidal coils.

A shock detector having an electrical detector having a set of water immersible electrodes for detecting hazardous water conditions through the determination of the presence of either an electrical current in a body of water, a voltage in the body of water or a voltage gradient in the body of water and then providing an alert to the existence of hazardous electrical conditions in the body of water which in some cases may transmitted to a power source to shut off a power source thereby removing the hazardous water condition.

A method for measuring the electric conductivity of a solution includes measuring voltage and current, calculating active value, deriving the calculation equation of electric conductivity, and calculation. Electric conductivity of solution is indirectly calculated by measuring consumption W of solution.

The invention provides a high-temperature melt physical property measuring device which comprises a physical property measuring system, a heating furnace, a lifting system, a vacuum and atmosphere control system, a temperature control system and a control display system.The physical property measuring system is used for obtaining measured data, the heating furnace is used for providing the data extraction environment, the lifting system is used for controlling the relative position of the physical property measuring system and the heating furnace, the vacuum and atmosphere control system is used for ensuring that the reaction atmosphere and pressure of the physical measuring system and the heating furnace are consistent, the temperature control system is used for controlling the reaction temperature in the heating furnace, and the control display system is used for processing the measured data and calculating and displaying high-temperature melt physical properties.The device can ensure that viscosity, density, surface tension and specific conductance of a high-temperature melt are rapidly and precisely measured at good heating rate under precise temperature control.