36 results about "Dielectric spectroscopy" patented technology

The invention discloses a method for evaluating ageing state of paper oil insulation. The method is characterized by comprising the following steps of: 1, measuring a relative dielectric constant and a dielectric loss factor of a paper oil insulation test product by adopting a frequency domain dielectric spectroscopy method; 2, establishing a composite exponential function relational expression of the relative dielectric constant and insulation paper polymerization of the paper oil insulation test product, and a composite exponential function relational expression of the dielectric loss factor and the insulation paper polymerization of the paper oil insulation test product; and 3, evaluating the ageing state of a paper oil insulation system by using the relational expressions. A device provided by the invention is simple in structure, is easily implemented, and is greatly improved in accuracy.

An apparatus for estimating a property of a downhole fluid, the apparatus includes: a carrier configured to be conveyed through a borehole penetrating the Earth; a downhole fluid extraction device disposed at the carrier and configured to extract the downhole fluid; and a dielectric spectrometer disposed at the carrier and configured to transmit electromagnetic energy into the extracted downhole fluid at a plurality of frequencies and to measure a plurality of responses to determine a permittivity of the extracted downhole fluid as a function of frequency; wherein the permittivity is used to estimate the property.

The invention relates to a method for assessing an insulation state of oil paper based on characteristic quantity of frequency domain dielectric spectroscopy. The method comprises following steps: utilizing a linear medium response equivalent circuit to simulate polarization characteristics of the insulation state of oil paper for a transformer and setting up the relationship between linear medium response equivalent circuit parameters, frequency-domain characterization complex capacitance and dielectric loss factors; then, utilizing complex capacitances with high frequency bands and a parametric equivalent circuit model for dielectric loss characteristic quantity and finally, integrating dielectric loss curves with low frequency bands at prediction sections, wherein the range of frequency bands in a dielectric loss frequency domain is equally divided into n frequency points (n larger than or equal to 1), n frequency points correspond to n dielectric loss integral value and n frequencies and corresponding dielectric loss integral value are fitted to a function curve. The method for assessing an insulation state of oil paper based on characteristic quantity of frequency domain dielectric spectroscopy has following beneficial effects: in order to obtain much more insulation information carried by dielectric loss factors within the limited measurement frequency domain, integrals of dielectric loss factors are utilized in the predicted low-frequency section as characteristic parameters for assessment of insulation state; and dielectric loss integral value within the low-frequency stage obtained by calculations is utilized for determining the insulation aging state of oil paper.

The invention provides a method which is used for measuring the octane value of petrol, based on the dielectric spectroscopy, and which relates to a method which adopts the dielectric spectroscopy to build a correction model of petrol of different compositions. The model is used for measuring the octane value of petrol. The method includes the following steps: 1, collecting modeling samples and data of dielectric spectroscopy; 2, pre-treating the modeling samples and the data of dielectric spectroscopy; 3, classifying the modeling samples; 4, respectively building correction models of various categories according to the results of cluster analysis; 5, verifying and correcting the correction model; and 6, predicting the unknown octane of the samples. The octane value of petrol is an indicator which is used for measuring the anti-knock performance of the petrol. The measurement method of the octane value of petrol has significance in the production and application of the petrol. The method can rapidly and efficiently determine the octane value of petrol within 5 minutes; the detection process is conducive to environmental protection; the samples require no pre-treatment; the analysis has the advantages of high speed and high reliability; the method can be used conveniently; and the costs of analysis are low.

A method for determining a concentration of at least one component of milk includes measuring impedance values between two electrodes associated with a cell containing a milk sample at each of at least three frequencies, and estimating a concentration of the at least one component from a polynomial expression in which the impedance values at the at least three frequencies are variables. A system for determining a concentration of at least one component of milk includes a sampling cell including a milk sample, electrodes operative to electrify the milk sample with excitation signals at a plurality of frequencies including at least three frequencies, a signal generator for generating the excitation signals, circuitry for determining a relationship between an amplitude and phase of reflected and incident signals obtained from the signal generator, and a processor that receives the relative amplitude and phase and estimates a concentration of at least one component of milk based on a polynomial expression relating measured impedance values at a plurality of frequencies to concentrations of at least one component of milk.

An apparatus for estimating a volume fraction of a formation fluid in a sample having a filtrate contaminant includes: a carrier configured to be conveyed through a borehole; a downhole fluid extraction device disposed at the carrier and configured to extract a sample of a formation fluid through a wall of the borehole; and a dielectric spectrometer and configured to transmit electromagnetic energy into the extracted sample at a plurality of frequencies and to measure a plurality of responses to determine a permittivity of the extracted sample fluid as a function of frequency. The apparatus further includes a processor configured to receive the permittivity of the extracted sample as a function of frequency from the dielectric spectrometer and to estimate the volume fraction of the formation fluid using a permittivity at a selected frequency in the plurality of frequencies for the sample as measured by the dielectric spectrometer.

The invention discloses a non-contact composite material frequency domain dielectric spectroscopy measurement method. The method comprises the steps that test voltage, frequency range and a frequency interval parameter are input into a dielectric spectroscopy tester through preset software as required; a composite material is placed between test electrodes; the height of the top electrode is adjusted, so that the distance between the electrodes is greater than the thickness of the composite material, namely the dielectrics of the composite material and air exist between the electrodes at the same time; variable frequency voltage excitation is applied on the electrodes, and at the same time current is measured, so as to calculate complex capacitance at the simultaneous presence of air and the composite capacitance under corresponding frequency; the composite material is removed from the electrodes, so that only the dielectric of air exists between the electrodes; variable frequency voltage excitation is applied on the electrodes, and at the same time current is measured, so as to calculate complex capacitance at the presence of air under corresponding frequency; and a complex dielectric constant and dielectric loss angle tangent of the composite material are calculated according to a formula. The method has the advantages that the polarization loss of the material is accurately measured and the like.

Cell or tissue permeability to electrical signals can be used to determine the depth of anesthesia of a patient. A method and device is presented to measure, record and control the effects of anesthesia or analgesics on humans and/or animals. Based on impedance values of tissues measured at single, multiple, or a domain of frequencies, the system detects tissue permeability alterations as determined by electromagnetic, impedance, and/or dielectric spectroscopy. The system measures the permeability of tissues to electrical signals and correlates these values to the depth of anesthesia or sedation level of a certain tissue or individual. This method and device can be used to measure the effects of anesthesia or analgesic for either local or systemic administration.

A method for measuring membrane potential using dielectric spectroscopy is described. A new theoretical model allows for the determination of membrane potential from low-frequency impedance measurements to provide a non-evasive method which is both rapid and inexpensive.

The invention relates to method for estimating the parameters of ZnO-varistor-equivalent circuit model based on FDS, belonging to the technical field of lightning arrester model. The method comprisesthe following steps. S1: The measuring instrument of frequency domain dielectric spectroscopy (FDS) and the ZnO varistors are prepared as a part of the experiment platform. S2: The parameters are properly set on the measuring instrument of frequency domain dielectric spectrum. S3: The FDS of the ZnO varistors are measured multiple times until the final results are obtained. S4: The complex impedance of the equivalent model is calculated using ZnO-varistor-equivalent polarized circuit model. S5: The parameter function of the equivalent model is optimized based on the measured FDS data of ZnO varistors and the results calculated by the model. S6: The iterative calculation on the optimized parameter function is performed using genetic algorithm to finalize the parameter estimation for the equivalent model. The method of the invention satisfactorily describes the dielectric response of ZnO varistors, and remediates the insufficient explanations by R C parallel model and the IEEE model on the microscopic behavior of ZnO varistors in terms of polarization and electric conductance among others.

The invention discloses an earth dielectric spectrum detecting method. The earth dielectric spectrum detecting method comprises the steps of segmenting a dielectric spectrogram of a detected region toobtain an actually detected dielectric spectrogram and calculating a perfect dielectric spectrogram; and further correcting a perfect complex dielectric constant analytic formula through a model function to obtain an actual earth complex dielectric constant analytic formula. A dielectric spectroscopy is introduced in earthquake precursor observation, and is a new active fault and crustal movementobservation method; the earth dielectric spectrum detecting method can be used for earthquake safety evaluation and earthquake precursor monitoring of a key project; and in underground fluid precursor observation, the method has wide application prospect.

A rapid virus and pathogen detector using RF and Dielectric Spectroscopy. The targeted virus or pathogen is identified by active illumination by RF energy and analysis of the response RF signal.

The invention discloses a method for rapidly detecting the content of polar components in frying oil. The method comprises the following steps: taking linear measuring points of a to-be-detected frying oil sample by utilizing a frequency domain dielectric spectroscopy tester, obtaining a compound dielectric constant of the frying oil sample, wherein the compound dielectric constant comprises a real part epsilon' and an imaginary part epsilon'', and forming dielectric constant-frequency and dielectric loss-frequency spectrums; and performing spectrum unfolding, fitting the actually measured dielectric constant, and judging the content of the polar components in frying oil according to an extracted characteristic parameter tau. According to the method disclosed by the invention, the content of the polar components in the frying oil can be rapidly measured in case of a nondestructive sample, and a reliable basis is provided for accurately evaluating the safety of fried foods.