186results about How to "Reduce measurement uncertainty" patented technology

The invention relates to a double-channel digital phase noise detection device and a phase noise detection method. An input sinusoidal signal from 1 to 100MHz is subjected to work distribution and phase shift, then double-channel quadrature sampling and digital signal processing technologies are utilized to extract phase noise in real time, so that the problem that the Fourier frequency is required to be corrected and calibrated and subjected to other testing links in the traditional measurement method is solved, an orthogonal reference source with the same frequency as a source to be tested is not required, and through utilizing a fixed reference source, the phase difference between the source to be tested and the reference source can be accurately measured in real time.

The invention provides a vector measurement method for passive intermodulation interference. The vector measurement method for the passive intermodulation interference comprises the steps that firstly a computer module adjusts the output frequency of a frequency reference unit, and a frequency reference signal is output; the frequency reference signal is used by a first signal source, a second signal source and a local oscillator source module after power division is conducted on the frequency reference signal, and then a testing signal with a frequency F1, a testing signal with a frequency F2 and a local oscillator signal L0 are generated; a part of the testing signal F1 and a part of the testing signal F2 are amplified by an amplifier module after power division is conducted on the testing signal F1 and the testing signal F2, then the signals are combined to generate a +43dBm dual-tone signal used for testing, reciprocal mixing is conducted on the other part of the testing signal F1 and the other part of the testing signal F2 after the other part of the testing signal F1 and the other part of the testing signal F2 pass through a frequency multiplication module, the frequency of an obtained signal is 2F1-F2 after filtering, and the signal is received by a reference receiver to serve as a PIM reference signal. By the adoption of the vector measurement method for the passive intermodulation interference, self-intermodulation and self-calibration of an instrument can be achieved, vector compensation for the self-intermodulation of the instrument can be achieved, the self-intermodulation of a system is greatly reduced, the measurement range of the system is widened, and the uncertainty of measurement is reduced; the time-frequency conversion technology can be directly adopted by a measurement result, and the time domain response to a PIM product can be observed.

The invention discloses a water cooling balance which comprises a rod-type balance and a water-cooled jacket. Two water flow pipelines are arranged in the rod-type balance. The two ends of each water flow pipeline are arranged on the two end faces of the rod-type balance respectively. A switching joint is arranged between the water-cooled jacket and the rod-type balance and fixed to one end face of the rod-type balance through a screw. A water inlet switching pipeline and a water outlet switching pipeline are arranged on the switching joint. One end of the water inlet switching pipeline and one end of the water outlet switching pipeline correspond to openings of the two water flow pipelines on the end faces of the rod-type balance in position and the other end of the water inlet switching pipeline and the other end of the water outlet switching pipeline correspond to a water inlet and a water outlet of the water-cooled jacket in position. The defects that a corrugated pipe type water cooling balance is large in drag measurement error and inconvenient to install and use and a corrugated pipe is prone to being damaged and leaking water are overcome. In addition, due to the fact that corrugated pipe related devices are omitted, the length of the balance is reduced, the diameter of the balance is increased, the rigidity and the cooling effect of the balance are greatly improved, the temperature effect is reduced, and measurement uncertainty is obviously reduced.

The invention discloses an antenna phase center calibration system based on site insertion loss measurement, which comprises an open site, a reference antenna, an antenna phase center calibration processor, a GPIB (General Purpose Interface Bus) card, a vector network analyzer and an antenna lifting component. When a to-be-measured antenna is subjected to phase center calibration, site insertion loss between the to-be-measured antenna and the reference antenna under the antenna heights is used twice, and an offset of an antenna phase center of the to-be-measured antenna relative to a reference point is acquired by a reflection wave path-reflection coefficient invariant strategy and an antenna phase center mean convergence criterion. The system aims at providing a calibration method for an open site antenna phase center. According to the system and the method, the antenna with the precise and known antenna phase center serves as the reference antenna, so that phase center calibration of the to-be-measured antenna is achieved; a phase center calibration mode depending on the reference antenna facilitates quantity value transmission of an antenna phase center parameter; and quantity value unification of the antenna parameter is achieved.

Methods and systems for determining the amount of water in a high water cut crude petroleum flow stream exiting from a hydrocarbon well. Electrical property measurements such as permittivity measurements are collected with a microwave analyzer system as high water cut oil exits from a well. Collection is continued until the span of the measurements of at least one property reaches at least a characteristic pre-determined value. A heuristic salinity of the water phase of the crude oil can then be determined based on the span statistics and reference equations and/or reference data. The flow-weighted average water content of the oil can then be determined using the heuristic salinity to correct for salinity variation as the output of the well changes over time.

The invention provides an attitude precision estimation method of multiple high-accuracy inertial navigation systems. According to the method, a set of laser tracker, an attitude measuring head, a signal generator, a swing table or turntable, and a data recording device are used to realize the attitude precision estimation of multiple high-accuracy inertial navigation systems at the same time through initial alignment calibration and synchronous data acquisition, wherein the swing table or turntable is used for providing a dynamic swing environment and can realize pitching, horizontal rolling and longitudinal swing according to a given period and amplitude value, the laser tracker and components matched with the laser tracker can measure three attitude angles of the swing table under a geographical system in real time, the signal generator sends TTL (transistor-transistor-logic) synchronizing level to the laser tracker and the laser inertial navigation systems so as to trigger data output, and the data recording device is used for receiving attitude data sent by the laser tracker and the inertial navigation systems in real time and storing the attitude data into lines. The method is quite suitable for the attitude precision estimation of the laser inertial navigation systems and can be used for estimating the attitude precision of multiple high-accuracy laser inertial navigation systems at the same time by using simplest equipment components.

The invention relates to a device and a method for calibrating a flow-dividing vacuum leaking hole, in particular to the device and the method for calibrating the vacuum leaking hole, the leakage value of which is less than 1*10-8 Pa.m3/s by adopting flow-dividing technology, and belongs to the field of measuring technology. The device consists of the calibrated leaking hole, a valve, an ionization gauge, a small hole, a flow-dividing chamber, a non-evaporable getter pump, an ultrahigh vacuum calibrating chamber, a metering hole, a very high vacuum pumping chamber, an oil-free bi-turbo molecular pump air exhauster set, a quadrupole mass spectrometer, a flow meter, a super-high vacuum calibrating chamber, the metering hole, a super-high vacuum pumping chamber and a common molecular pump air exhauster set. The method adopts a fixed flow method gas micro-flow meter to provide a known gas flow rate, so the measuring range of the flow rate is wide and uncertainty of the measurement is low; and by adopting a flow-dividing method to calibrate the vacuum leaking hole, the method of the invention completely avoids a nonlinear error of the quadrupole mass spectrometer and can precisely calibrate the vacuum leaking hole the leakage value of which is less than 1*10-8 Pa.m3/s.

The invention provides an integrated standard device for field calibration of an extra/ultra high voltage capacitor voltage transformer (CVT). The device comprises a test power supply, a test lifting platform, a standard appliance, a measuring instrument and a vehicle platform, wherein the test power supply comprises cascade upper and lower level test transformers, a secondary compensating reactor and a voltage regulator; the standard appliance comprises cascade upper and lower level standard voltage transformers and a high voltage isolated transformer; the test lifting platform comprises a base, transmission mechanisms and insulating support members; the measuring instrument comprises a transformer calibrator and load boxes; all the equipment is fixedly installed on the vehicle platform;and the test lifting platform can lift in the vertical direction. The upper and lower level standard voltage transformers in the standard device can troubleshoot the standard device by way of mutual calibration in the field and complete field calibration of the extra/ultra high voltage CVT, without unloading.

The invention discloses a high and low temperature vacuum calibrating device and a high and low temperature vacuum calibrating method and belongs to the field of measurement. The device comprises a standard vacuum gauge, a three-way connecting piece, a calibrated vacuum gauge, a high and low temperature vacuum calibrating chamber, a monitoring vacuum gauge, a temperature control board, a refrigerating system, an air-bleed set, a valve, a gas supply system and a micrometering valve. According to the device and the method, the accurate calibration of the vacuum gauge at different temperature points in a temperature range of minus 140 DEG C to 100 DEG C in a range of 1*10<-4>Pa to 1*10<5>Pa can be implemented.

The invention provides a television imaging system modulation transfer function test device and method and belongs to the technical field of optical measurement. The television imaging system modulation transfer function test device and method are characterized in that a television imaging system to be tested is placed in an optical collimation system illuminated by an integrating sphere light source, of which the light intensity is adjustable and which is high in space uniformity, and slit targets are arranged in the focal plane of the optical collimation system; the slit targets, after passing through the optical collimation system and the television imaging system to be tested, are imaged to a target surface of the television imaging system; and after an image recording and processing system carries out a series of calculation and processing on the slit images, line spread function distribution of the slit targets and the MTF value are obtained, and thus MTF measurement of the television imaging system is finished.

The invention discloses a high-precision laser divergence angle parameter calibration device. A to-be-tested laser (1) is focused through a lens (6) after being reflected through an optical flat (3) and a spectroscope (2); a converge light is divided into two testing light paths of transmission and reflection after passing through a beam splitter (7); when a focus light spot not exceeds a photosurface of a CCD camera (8), the testing light path is the transmission light path; the CCD camera (8) is located at a lens focal plane position, and the focal spot diameter is calculated by a formula (2); conversely, the testing light path is reflecting light path; a ground glass screen (9) is located at the lens focal plane, an imaging system (10) images the light spot on the ground glass screen (9); the focal spot diameter is calculated by the formula (2). A calibration parameter fn is substituted; a formula (3) is used for calculating the divergence angle of the to-be-tested laser; according to the established confusion disc model base, the collected focal spot is performed with confusion disc spreading and superposition; thus the measurement uncertainty introduced by aberration and light path imbalance of the lens (6) is evaluated.

The invention relates to a measurement method for the leak rate of pressure leak, belonging to the measurement technical field. A leak rate measurement device for pressure leaks adopted by the measurement method is composed of four vacuum valves 1, 3, 5, 11, an absolute pressure meter 2, a pressure leak 4, a piston 6, a volume-varied chamber 7, a pressure differential pressure meter 8, a volume-varied chamber body 9, a standard container 10, a vacuum pump 12 and a gas bottle. The measurement method utilizes the motion of the piston in the volume-varied chamber to change the capacity of the volume-varied chamber, to keep the pressures of the volume-varied chamber consistent at the start and the end of the measurement; and measures the pressure of the volume-varied chamber, the sectional area of the piston, the motion distance of the piston, and the experiment time to calculate the leak rate of the pressure leak. The pressure change curve of the volume-varied chamber is in saw tooth form. The measurement method can measure the leak rate not higher than 5x10 Pam3/s, has short measurement time, reduces the measurement uncertainty from prior 9.1% to 5%, and improves working efficiency.

The invention discloses a method for measuring the sight line stabilizing accuracy of a photoelectric sight-stabilizing system, and belongs to the technical field of optical measurement. The method is characterized by comprising the following steps that: a plane reflector is fixed on an inner ring frame of the photoelectric sight-stabilizing system to be measured, the photoelectric sight-stabilizing system to be measured is in a vibration state, a measuring laser beam is subjected to strength stabilization, spatial filtering and collimation and then irradiates the plane reflector, a complementary metal oxide semiconductor (CMOS) camera transmits a light spot image sequence of a reflected light beam imaged on a target surface to an image recording and processing system, and the image recording and processing system performs a series of processing on the light spot image sequence to obtain a light spot center-of-mass coordinate sequence, a stabilizing accuracy value sequence and stabilizing accuracy value sequence standard deviation, so that the stabilizing accuracy is measured. By the method, the high-accuracy measurement of the sight line stabilizing accuracy of the photoelectric sight-stabilizing system is realized; and the method can be popularized to the fields of measurement of the stabilizing accuracy of a gun control system and the like, and is wide in application prospect.

The invention discloses a value defining method for a microsphere fluorescent intensity standard substance. The method comprises the following steps: (1) preparing a microsphere fluorescent intensity standard substance; (2) measuring purity of fluorescein powder to calculate and prepare fluorescein standard mother liquid; (3) regulating a fluorospectro photometer; creating a calibration curve of an instrument fluorescent responding value and fluorescein density; (4) measuring granular quantity density of the microsphere fluorescent intensity standard substance; (5) measuring fluorescent responding value of a sample; calculating fluorescein density of the sample and fluorescent molecule quantity MESF carried by each microsphere fluorescent intensity standard substance granular. The value defining method is provided with favorable accuracy, reliability and traceability of value.

A sensor is provided that includes a first optical body having at opposing, spaced sides an incident surface and a reflecting surface. The sensor includes an optical pathway for carrying incident light to the incident surface. The first optical body acts as a Fabry-Pérot etalon, such that a portion of the incident light passes through the incident surface, reflects from the reflecting surface, and then returns along the optical pathway. The first optical body is formed of a material whose optical absorbance increases depending on the neutron fluence experienced by the material, such that a corresponding characteristic attenuation is produced in the reflected light returned along the optical pathway depending on the neutron fluence experienced by the first optical body. The sensor may measure pressure in combination with the measurement of temperature and neutron fluence, and a further sensor is provided for combined measurement of pressure and neutron fluence.

The invention discloses a low-temperature absolute radiometer absolute spectral responsivity calibration method and an experimental apparatus. The experimental apparatus mainly comprises a main light path unit, a swing module unit, a low-temperature absolute radiometer, a detector vacuum chamber and a main control computer. The method includes the steps that a standard transmission detector and the low-temperature absolute radiometer are placed in the same vacuum environment and driven and controlled by an arc-shaped guide rail so that the low-temperature absolute radiometer and the standard transmission detector can pass through the same light path transmission path, the received incident light powers are completely the same, therefore, the influence of uncertainty in the process of measurement of window transmittance is eliminated, accuracy in the standard transmission process of the low-temperature absolute radiometer will be greatly improved, and the high-precision calibration of the absolute spectral responsivity of the standard transmission detector in the range between the ultraviolet band and the infrared band is achieved.

The invention discloses a device and a method for measuring a volume ratio of a vacuum container by a linear vacuometer, and belongs to the technical field of measurement. The device comprises a pressure stabilizing chamber, a vacuum valve, a container, a vacuometer, an air bottle and a vacuum pump. The vacuum container is vacuumized, and gas flows in the vacuum container; and the vacuum pressure is measured by the vacuometer. The device for measuring the volume ratio of the vacuum container by the linear vacuometer has a simple structure; because only one linear vacuometer is used, components causing measurement uncertainty are less; the linear vacuometer for measuring the vacuum degree is not required to measure absolute pressure, and a calibration coefficient thereof is not required to be known, so the uncertainty due to calibration is avoided; and the method for measuring the volume ratio of the vacuum container is simple, and has low measurement cost and small measurement uncertainty.

The invention relates to a measuring device and method for infrared spectral radiation characteristics of high-temperature particles, relating to a measuring device and method for infrared spectral radiation characteristics of dispersed particles, which solves the problem that the prior art cannot measure the natural state particle radiation characteristics in the high-temperature continuous spectrum range. The invention adopts the environmental compensation algorithm, realizes the measurement of the spectral equivalent transmittance of high-temperature particles in the natural state, determines the applicability of the measurement of the radiation characteristics of high-temperature particles in the continuous spectrum range, and provides a basis for further inversion of the complex refractive index of high-temperature particles The research provides reliable experimental data and experimental devices, and the measurement uncertainty of the present invention is less than 2%. The invention can be widely used in the fields of chemical industry, metallurgy, power, construction, medicine, biology, food, aerospace, military affairs, atmospheric science and the like.

The invention discloses a device and a method for measuring volume ratio of a vacuum container and belongs to the technical field of measurement. The device comprises a gas cylinder, a first vacuum valve, a pressure stabilizing chamber, a second vacuum valve, a small container with unknown volume, a first thermometer group, a third vacuum valve, a large container with unknown volume, a second thermometer group, a vacuum gauge, a fourth vacuum valve and a pumping system. The device is simple in structure and reduces the uncertainty of measurement by introducing temperature correction in the measurement process. The method is simple, the measurement cost is low, and the uncertainty of measurement is small.

The invention discloses a high-power microwave coupling measuring apparatus. The apparatus comprises a flange, a main waveguide, a coupling waveguide, an electric probe, an insulating support structure, a coaxial outer conductor and a radio frequency coaxial connector. The electric probe, the coaxial outer conductor and the insulating support structure form a waveguide of a coaxial structure, and the electric probe is fastened inside the coaxial outer conductor in a coaxial manner by means of the insulating support structure. The main waveguide is directly connected to a high-power microwave source microwave output pathway or a high-power microwave reception antenna through the flange. The coupling waveguide, connected to the main waveguide and the coaxial outer conductor, conducts a small amount of coupling sampling on high-power microwave signals in the main waveguide, and further feeds in the coaxial structure formed by the electric probe and the coaxial outer conductor. The radio frequency coaxial connector is connected to the coaxial outer conductor and an external coaxial cable. Through the technical scheme of the invention, the measuring apparatus is improved in power capacity and reliability.

The invention discloses a special worktable for a laser tracker, which is capable of moving the laser tracker to an extension line of the link between the point A and the point B to the utmost extent and keeping the pointing direction of the laser track consistent with the link between the point A and the point B to the utmost extent when in measurement of the distance between the point A and the point B in the three-dimensional space. The special worktable for the laser tracker comprises a mount, a vertical angle regulator, a horizontal angle regulator, a horizontal translation regulator and a lifting regulator, wherein the mount is matched with a base of the laser tracker, the vertical angle regulator, the horizontal angle regulator, the horizontal translation regulator and the lifting regulator are used for regulating the mount. The interferometry function of the laser tracker can be utilized by the worktable during measurement, horizontal rotation and vertical rotation of the laser tracker are avoided, and accordingly uncertainty in measurement of the laser tracker is reduced, and measurement precision of the point A and the point B is guaranteed. In addition, the invention further discloses a laser tracking measurement method.

The invention belongs to the technical field of aero-engines and particularly relates to a real thrust measuring and calculating method for test run of an aero-engine on an indoor test bed. The real thrust measuring and calculating method specifically comprises the steps of 1 determining the spatial position of a control body, 2 arranging a rear cross section measuring point on a lip rear cross section (2), 3 arranging front cross section measuring point on a far front cross section (1), 4 obtaining wind speed values and static pressure values on the measuring points, and 5 obtaining a real thrust value of the test run of the aero-engine on the indoor test bed. According to the real thrust measuring and calculating method, the area of air intake cross section of the engine is reasonably selected, the flow pipe surface for air flowing in a test run workshop serves as a control face, an air intake channel additional resistance correction formula is derived and real thrust is calculated by applying momentum theorem. The real thrust measuring and calculating method has the advantages of being clear in control body division, fewer in correction terms, simple and convenient to calculate and the like, and the problem of real thrust measurement and calculation during the test run of the aero-engine on the indoor test bed can be solved.

The invention provides a calibration system and method of a pulse power standard, and overcomes the problems such as pulse waveform distortion, and mismatching between a radio-frequency source and a power meter in a pulse power meter calibration factor testing process. In the calibration system of the pulse power standard, the pulse power standard is used for generating a radio-frequency signal, and a waveform analysis module analyzes a pulse envelope and calculates a waveform correction coefficient; a reflection analysis module tests and calculates a reflection coefficient; and a control and data handling module controls a radio-frequency pulse signal, collects test data, calculates a calibration factor, analyzes precision, and accesses data. The calibration method of the pulse power standard comprises the steps of: test condition control, waveform correction coefficient testing, reflection coefficient testing and power testing, calibration factor calculation, precision analysis and the like. By collecting, storing, analyzing and correcting the test data in real time, the measurement uncertainty is lowered, the test processing is simplified, the test efficiency is improved and the precision is improved.