106results about How to "Suitable for measurement" patented technology

The invention discloses a method for measuring zero-sequence parameters of double-circuit transmission lines. The method comprises the following steps: measuring the zero-sequence parameters of the double-circuit transmission lines in the manner of live line measurement or power cut measurement; by utilizing the global positioning system technology, simultaneously measuring the zero-sequence voltage and the zero-sequence current at the head ends and the tail ends of the double-circuit transmission lines to realize synchronous sampling on the zero-sequence voltage and the zero-sequence current; and then, working out the respective zero-sequence self impedance and zero-sequence self capacitance, and zero-sequence mutual impedance and zero-sequence mutual capacitance between the double-circuit transmission lines. In the method for measuring the zero-sequence parameters of double-circuit transmission lines, the distributed parameter models of the double-circuit transmission lines are established, and the influences of distributed capacitors on measured results are considered, thereby, the accuracy of the measured results of the zero-sequence parameters of the double-circuit transmission lines is greatly improved.

The invention discloses a rapid measuring method for the growing height of agricultural crops in mountainous areas based on an unmanned aerial vehicle photographed image. The method comprises the following steps: acquiring the geographical coordinates of all ground control points and the surface elevation value H; acquiring an initial image P1 and a measurement image P2; establishing elevation dense point clouds; generating respectively a ground splicing image and digital surface model data; generating a three-dimensional model for an agricultural crop growing area and extracting from the three-dimensional model the bare soil elevation value and the measurement elevation value; and outputting the growing height of the agricultural crops. According to the invention, through an unmanned aerial vehicle, it is possible to obtain what is influential in the growing process of agricultural crops; and through the cooperation with the ground control points, DSM data are generated and a three-dimensional model is obtained; and from the three-dimensional model, the growing height of the agricultural crops in each period can be further obtained. With a spatial analysis method to extract the growing height of agricultural crops, the method does not require much on the terrains, therefore, making it suitable for the height measurement of different types of agricultural crops in different growing periods. Capable of measuring at a short time, the method also achieves high efficiency and good measurement precision.

This invention is variable density fibre complex conductivity in situ synthesis measuring method and device. Apply force on fibre plug, change the density of the fibre plug, and apply air, voice, electricity, heat, humidity effects. And use force, air, voice, electricity, heat, humidity sensor to measure the change of the physical appearance density and distribution. The device can improve the structure and isolation of the push silo, fiber plug and measure chamber, and add measure units , related drive and control circuit, modular used for data collection and treatment and interface control, in push silo and measure chamber. This device can actualize the conduction, isolation of variable density fibre complex's in situ synthesis measurement. This measurement has high accuracy and little disturbance. It can be widely used in many kinds of measurement.

The invention relates to a fiber Bragg grating vortex shedding flow meter based on a triangular prism-shaped vortex-forming body and a using method thereof, and belongs to the technical field of photoelectronic measurement. The fiber Bragg grating vortex shedding flow meter is characterized in that the triangular prism-shaped vortex-forming body is fixed inside a measuring tube through bases at the two ends, and the two side faces at the middle part of the triangular prism-shaped vortex-forming body are communicated with each other, so as to form a pressure guide cavity; in the pressure guide cavity, a free end of a constant strength cantilever is provided with a mass block, and a fixed end of the constant strength cantilever is connected with an axial conduit inside the triangular prism-shaped vortex-forming body; and the fiber Bragg grating is stuck to the central axis of the surface of the constant strength cantilever, and the fiber Bragg grating is connected with an external fiber through an axial conduit and a fiber out-leading hole. The fiber Bragg grating vortex shedding flow meter based on the triangular prism-shaped vortex-forming body provided by the invention has the beneficial effects that by adopting the triangular prism as the vertex-forming body, very high reliability is provided for flow detection; and by adopting the fiber Bragg grating as a sensing element, the meter can resist electromagnetic disturbance, is suitable for measuring the flow of various fluid, and particularly has a very good prospect for measuring the flow of fluid with chemical corrosion.

A uniform velocity tube of flow rate transducer consists of high pressure sampling hole at flow receiving surface, low pressure sampling hole at side surface between flow receiving surface and flow departing surface which are built on tube wall of the uniform velocity tube . It features that the said tube section is prepared to be a bullet head form so fluid is splited along two side surfaces of said tube section formed as bullet head to make a flow coefficient relatively stable when fluid flows through the tube.

The invention provides a thin film test sample platform of an X-ray diffraction instrument. The thin film test sample platform is formed by a fixing bracket, three springs, a flat plate type sample holder and an adjusting screw, wherein the fixing bracket is in a right-angle Z shape; a screw hole and three spring hook holes are formed in the center of a flat plate below the fixing bracket; three spring pull hook holes are also formed in the flat plate type sample holder; the flat plate type sample holder passes through the three springs to be respectively connected with the fixing bracket through the pull hook holes; the adjusting screw penetrates through the screw hole of the fixing bracket to be contacted with the lower bottom face of the sample holder; the height of the sample holder can be freely adjusted through the adjusting screw; finally, the surface of a sample and the upper surface of the fixing bracket are on the same plane. According to the thin film test sample platform, X-ray diffraction measurement of the samples with the different specifications can be conveniently carried out, and particularly, the X-ray diffraction measurement of thin film samples with different substrate thicknesses can be realized.

A nuclear density gauge and test method is provided for measuring density material in a relatively thin zone beneath a surface of the material. The gauge comprises a gauge housing and a substantially planar base on said gauge housing adapted to be positioned on a surface of the material sample. A gamma radiation source having a characteristic primary energy and an activity of no more than 100 microcurie is mounted within the housing and cooperates with the base for emitting gamma radiation through the base and into an underlying material sample. An energy selective gamma radiation detector is mounted within the gauge housing and in laterally spaced apart relation from the gamma radiation source. The gamma radiation detector is operable for quantifying the energy level of the detected gamma radiation. Shielding is provided within the gauge housing between the source and the detector for preventing gamma radiation from passing directly from said source to the detector. An analyzer is connected to the detector for detecting gamma radiation counts in a predetermined energy spectrum having a lower limit of 0.1 MeV or greater and an upper limit which is less than the characteristic primary energy of said source. The density of the sample is calculated based upon the gamma radiation counts obtainedby the analyzer within the predetermined energy spectrum.

The invention discloses a mixed-pressure bipolar direct-current power transmission line zero-sequence parameter precisely measuring method. Bipolar head ends and tail ends of direct power transmission lines different in voltage level are respectively connected, zero-sequence voltages and zero-sequence currents on head and tail ends of the mixed-pressure bipolar direct-current power transmission lines are simultaneously measured, and a global satellite positioning system is utilized to realize synchronous sampling of voltages and currents on double ends of the mixed-pressure bipolar direct-current power transmission lines; and then zero-sequence self-impedance, zero-sequence mutual-impedance, zero-sequence self-capacitive-reactance and zero sequence mutual-capacitive-reactance of the mixed-pressure bipolar direct-current power transmission lines are obtained by means of calculation. According to the invention, a distributed constant model of the mixed-pressure bipolar direct-current power transmission lines is established, and the influences of distributed capacitance on the measuring result are considered, so that the precision of mixed-pressure bipolar direct-current power transmission line zero-sequence parameter measurement is substantially improved.

The invention relates to the measuring technique for dielectric medium dielectric coefficients under microwave frequency, and discloses a medium dielectric coefficient measuring probe with a coaxial line structure under the high-temperature condition, wherein the measuring probe is used for measuring medium dielectric coefficients under the high-temperature condition. According to the technical scheme, the medium dielectric coefficient measuring probe with the coaxial line structure under the high-temperature condition comprises a measuring section and an interface section, wherein one end of the interface section is connected with the measuring section, the other end of the interface section is of a coaxial joint structure, media between an inner conductor and an outer conductor of the interface section are high-temperature resistant heat insulation solid media, the inside diameter of an outer conductor of the measuring section is slightly smaller than that of the outer conductor of the interface section so that the high-temperature resistant heat insulation solid media can be prevented from falling off and microwave reflection can also be reduced, the space between an inner conductor and the outer conductor of the measuring section is of a hollow structure, and the inner conductor and the outer conductor of the measuring section and the inner conductor and the outer conductor of the interface section are coaxial. The measuring probe is suitable for measurement of dielectric coefficients of matter under the high-temperature condition, and is high in measurement accuracy within a wide frequency band range.

The invention discloses a novel capacitive liquid level sensor based on the capacitance calculation principle and the application thereof. The novel capacitive liquid level sensor comprises a shielding cover, an insulator, a metal layer, an upper packaging piece, a circuit board, a special metal pin and a lower packaging piece. The insulator is shaped like a barrel, and the outer surface of the insulator is plated with the metal layer. The shielding cover is coaxial with the insulator and located on the periphery of the insulator, and the insulator and the shielding cover are assembled together through the upper packaging piece and the lower packaging piece. A positioning and clamping surface is arranged outside the upper packaging piece, and the signal processing circuit board is arranged inside the positioning and clamping surface. Small holes through which liquid can flow are evenly distributed in the shielding cover. Based on the capacitance calculation principle, the precision of the capacitive liquid level sensor is only influenced by the relative dielectric constant of the liquid to be measured and the relative dielectric constant of air and is expected to be improved than that of a traditional capacitive liquid level sensor, and the novel capacitive liquid level sensor is also suitable for measurement of the level of ultralow-temperature liquid.

The invention discloses a satellite radar altimeter tracker compatible of sea and land, which comprises a first FFT power analyzer, an MLE error discriminator, a first Alpha-Beta filter, a second FFT power analyzer, an OCOG error discriminator, a second Alpha-Beta filter and a data composing treatment unit; wherein, the first FFT power analyzer is electrically connected to the MLE error discriminator, the first Alpha-Beta filter and the data composing treatment unit. The MLE error discriminator is respectively connected with the first Alpha-Beta filter and the data composing treatment unit electrically. The first Alpha-Beta filter is electrically connected with the data composing treatment unit. The second FFT power analyzer is electrically connected with the OCOG error discriminator, and the second Alpha-Beta filter and the data composing treatment unit. The OCOG error discriminator is respectively connected with the second Alpha-Beta filter and the data composing treatment unit electrically. The second Alpha-Beta filter is electrically connected with the data composing treatment unit. The first Alpha-Beta filter is also electrically connected with the second Alpha-Beta filter.