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280results about How to "Reduce measurement error" patented technology

Laser detection device and method for gear parameters

The invention relates to a laser detection device and method for gear parameters. The laser detection device is characterized in that a worktable is provided with an internal point; a laser displacement sensor is arranged on a bracket; the bracket is arranged on a linear motor sliding block of a sliding table; the sliding table is arranged on an angular displacement rotating system and is fixedlyconnected to a rotating disk together with a rotating shaft; a casing of the angular displacement rotating system is arranged on a lifting arm through screws; the lifting arm is connected with the vertical surface of a machine body through a high-precision linear guide rail and a sliding block; a servo motor drives a ball screw which is fixedly connected to the vertical surface of the machine body to rotate; and a data acquisition and communication system is arranged on a rotating shaft upper plane of the angular displacement rotating system. Tested workpieces are subjected to data measurement, acquisition, transmission, reconstruction, separation, comparison and display to finish the full process of detection. According to the laser detection device and method, the non-contact and blind spot-free measurement is realized, the detection speed and measurement precision are improved; the difficult problem that a pinion is difficult to detect is solved; and in the measuring process, the gear is stationary and a measuring head does measuring movement, thus the measuring error caused by mounting the gear is reduced.
Owner:唐大春

Method for measuring various elements in food additive citric acid through ICP-MS

The invention belongs to the field of chemistry, and particularly relates to a method suitable for measuring 16 elements including lead, copper, iron, arsenicum, chromium, zinc, cadmium, manganese, nickel, cobalt, indium, rhodium, gallium, bismuth, neodymium and cerium in a food additive citric acid. The measuring method consists of the following steps: firstly, weighing a sample of the food additive citric acid, and putting the sample in a microwave digestion instrument; secondly, performing sample digestion by using a mixed acid of nitric acid and perchloric acid; thirdly, adding a sample solution into hyperpure water according to a proportion that 1 to 2 mL of the nitric acid is added into each 10 grams of the citric acid sample, and moving the mixture into a plastic volumetric flask of100 mL; fourthly, drawing calibration curves: using national standard stock solutions (GBW) containing the 16 elements, using 3 percent nitric acid to dilute the national standard stock solutions into mixed standard solutions with the concentrations of 0.0, 5.0, 10.0, 20.0, 30.0, 40.0 and 50.0 umg/L, and drawing the calibration curves of each elements by using the concentrations as horizontal coordinates and ion abundances as vertical coordinates; and fifth, measuring and calculating the contents of the 16 elements in the food additive citric acid in the sample solution obtained in the thirdstep according to the fourth step.
Owner:CHECKOUT & QUARANTINE TECH CENT YUNNAN ENTRY &EXIT CHECKOUT & QUARANTINE BUR

Motion type magnetic target locating method based on vector magnetic gradiometer

The invention discloses a motion type magnetic target locating method based on a vector magnetic gradiometer. The motion type magnetic target locating method comprises the following steps that (1) the structural error of two sets of vector magnetometers forming the vector magnetic gradiometer is compensated so that the signal output of the two sets of vector magnetometers is maintained to be consistent; (3) the vector magnetic gradiometer is enabled to rotate around a vertical axis in a magnetic abnormal space, the magnetic field direction gradient data of the magnetic gradiometer at the rotating azimuth angle are acquired, and magnetic field full tensors are acquired according to the relation between the direction gradient and the azimuth angle; and (3) magnetic target locating is performed by using the magnetic field full tensors. According to the motion type magnetic target locating method, the structural error compensation problem of the vector magnetic gradiometer is solved by using the mode of triaxial coefficient compensation so that the output of the two sets of vector magnetometers forming the magnetic gradiometer is enabled to be correspondingly consistent; and the structural error is eliminated so that high-resolution detection can be realized.
Owner:NAVAL UNIV OF ENG PLA

Microstructure resonant beam pressure sensor

InactiveCN101348233AHigh measurement accuracyReduce measurement errorTelevision system detailsForce measurement by measuring frquency variationsFrequency instabilityPhysics
The invention provides a micro-structure resonant beam pressure sensor, comprising an upper silicon slice and a lower silicon slice which are formed by linkage, wherein the upper silicon slice comprises a rectangular frame and two symmetrical peninsulas arranged in the rectangular frame; two groups of resonant beams which are made of titanium nitride and arranged side by side have two ends connected with the two peninsulas respectively; each resonant beam is respectively provided with a lead wire and a excitation resistance and a sensing resistance which are connected with electrodes; the lower silicon slice adopts a structure with an O-shaped frame, in which a pressure film arranged. In the invention, the titanium nitride is used as the resonant beams of the pressure sensor, and the titanium nitride has very high natural resonance frequency, the precision of the resonant type pressure sensor is greatly improved due to the use of the titanium nitride resonant beams. The measuring precision can be improved by increasing the natural resonance frequency, because higher the natural resonance frequency is, the bigger movement the corresponding zero pressure frequency has (the precision of the sensor is the specific value of the frequency instability and the movement of the corresponding zero pressure frequency) , and higher the measuring precision of the pressure is.
Owner:XI AN JIAOTONG UNIV

Experimental method for measuring unconventional tight gas reservoir spontaneous infiltration absorption relative permeability

ActiveCN109916799AReduce measurement errorThe data is accurate and reliablePermeability/surface area analysisWater saturationFormation water
The invention discloses an experimental method for measuring unconventional tight gas reservoir spontaneous infiltration absorption relative permeability. The method comprises the following steps of (1) washing and drying a core taken from a tight gas reservoir, and then measuring a diameter D, a length L, and an original porosity phi0; (2) obtaining absolute permeability K0 of the core and an effective pore volume VP; (3) putting the core after saturated formation water into a core holder, adding confining pressure, and raising a temperature to a formation temperature; (4) injecting a nitrogen gas into the core, carrying out replacement and stopping when a water amount of a water metering pipe at a core outlet end is no longer increased; and (5) under a water flooding pressure differencedeltaP, slowly injecting the water into the core holder, carrying out a spontaneous infiltration absorption water gas displacement experiment, calculating water phase relative permeability Krw, gas phase relative permeability Krg and water saturation Sw of the core, and acquiring a gas-water two-phase relative permeability curve of a tight gas reservoir core spontaneous infiltration absorption water gas displacement process. In the invention, a theoretical basis is provided for determination of residual gas saturation of the tight gas reservoir and calculation of reserves.
Owner:SOUTHWEST PETROLEUM UNIV

Drilling detecting integrated system and method for overlying strata fracture detection

The invention discloses a drilling detecting integrated system and method for overlying strata fracture detection, and particularly relates to the field of overlying strata fracture development regulation detection under a coal mine well. The invention aims at solving the defects exist in the existing overlying strata fracture detection that excavation, drilling holes and the overlying strata fracture detection can not be conducted simultaneously, a certain measurement error or even hole collapse occurs due to the fact that new cracks occur when the drilling holes are placed for a long time, and whether hole sealing is finished or not and the reliability of the hole sealing can not be verified artificially in the detection process. The drilling detecting integrated system comprises a detection pipe, a drilling device and a control device; the upper portion of a rod body of the detection pipe is sleeved with a hole sealing capsule, the two ends of the hole sealing capsule are fixed through upper convex plates and lower convex plates which are located on the detection pipe respectively, an electric three-way ball valve is arranged inside the hole sealing capsule, and a groove is formed in the portion, at the lower portion of one convex plate, of the rod body of the detection pipe.
Owner:SHANDONG UNIV OF SCI & TECH

Method for measuring shrinkage factor of PDP (Plasma Display Panel) glass

The invention discloses a method for measuring shrinkage factor of PDP (Plasma Display Panel) glass. The method comprises the following steps: step 1, marking out a measuring line on a PDP glass sampler sheet, and cutting the PDP glass sampler wafer into a reference sheet and a measuring sheet, wherein the cutting line cuts the measuring line; step 2, vertically placing the measuring sheet, arranging porcelain boats on the top and the bottom of the measuring sheet respectively, sealing and surrounding the measuring sheet, and filling flexible high-temperature resistant materials between the upper and the lower ends of the measuring sheet and the inner walls of the porcelain boats and between the side edge of the measuring sheet and the inner walls of the porcelain boats; step 3, heating the porcelain boats and the measuring sheet according to a preset heating curve in an integrated manner; step 4, carrying out annealing cooling to the measuring sheet after heating, comparing the displacement of the measuring line of the measuring reference sheet and the measuring sheet and calculating the shrinkage factor. The method for measuring the shrinkage factor of PDP glass can solve the problem of non-uniform heating and enables the whole piece of glass to be in a stable temperature environment during glass heat treatment to achieve uniform heat shrinkage effect, and furthermore, the measured shrinkage factor data is accurate and reliable.
Owner:SICHUAN XUHONG OPTOELECTRONICS TECH

Noninvasive and continuous blood pressure monitoring method and device based on pulse wave propagation time

The invention provides a noninvasive and continuous blood pressure monitoring method and device based on pulse wave propagation time. The noninvasive and continuous blood pressure monitoring method and device are characterized in that standard II-lead ECG signals of a testee is detected through an electrocardiosignal detection unit under three body positions, including the body positions generated when the testee lies on his/her back, stands with arms vertically lifted and stoops, meanwhile PPG signals at the ends of index fingers are detected through a volume pulse wave signal detection unit, the time difference between the wave peak value point R of the ECG signals and the characteristic point of the PPG signals is measured through an upper computer signal processing unit and serves as the pulse wave propagation time PTT, correlation analysis and linear-regression analysis are conducted on the obtained PTT data and blood data recorded by an electronic sphygmomanometer, a regression equation of the PTT to blood pressure is established, and the blood pressure value is obtained indirectly by measuring the PTT. By means of the noninvasive and continuous blood pressure monitoring method and device, accuracy of continuous blood pressure detection and comfort of the testee can be effectively improved, long-term noninvasive and continuous blood pressure measuring can be achieved, portability of the device is high, great convenience is brought to examination operation, and real-time detection of the blood pressure value is achieved easily.
Owner:SUN YAT SEN UNIV

Detecting and straightening machine and method for shaft parts

The invention discloses a detecting and straightening machine and method for shaft parts. The detecting and straightening machine comprises a console and a straightening machine body. The straightening machine body comprises a fixed work table and a movable main machine frame. The movable main machine frame can move on the fixed work table along the X axis and can feed data back to the console. A straightening hydraulic cylinder is arranged on the movable main machine frame and can straighten a workpiece. A rear bracket capable of moving along the Y axis is arranged on the rear side of the movable main machine frame. A measurement hydraulic cylinder is arranged on the rear bracket. A measurement rolling wheel is arranged below the measurement hydraulic cylinder. A displacement sensor for measuring the Y-axis movement amount and a displacement sensor for measuring the Z-axis movement amount are arranged on the movable main machine frame and the measurement hydraulic cylinder correspondingly. The displacement sensors can transmit information to the console. Detecting and straightening of the workpiece can be conducted on the same device and the same station through the same installation reference. When straightness detection is conducted on the workpiece, detection can be conducted on the workpiece on three-dimensional scale, and measurement errors are reduced.
Owner:SHANDONG UNIV

In-service bolt axial force detection method, detection system and detection device

The invention discloses an in-service bolt axial force detection method, a detection system and a detection device. The detection method comprises steps: the bolt diameter of a bolt sample, a thread diameter, a sound velocity before force, a nut axial length, a screw rod length, a bolt force bearing area length, actually-measured axial forces of the bolt sample under different loads, ultrasonic transit time corresponding to the actually-measured axial force, and an ultrasonic transit time-axial force model are acquired; according to the bolt diameter, the thread diameter, the sound velocity before force, the nut axial length, the screw rod length, each actually-measured axial force, the ultrasonic transit time and the ultrasonic transit time-axial force model, a soft measurement expressionis determined; and by adopting the soft measurement expression, the axial force of the to-be-detected in-service bolt is calculated. The detection method provided in the invention not only takes intoaccount the influences of material constants of the bolt on the bolt axial force, but also takes into account influences of the length of the nut force bearing area and a nut force bearing area internal axis normal stress factor on the bolt axial force, the axial force of the in-service bolt can be effectively measured, the measurement errors are small, and the precision is high.
Owner:BEIJING JIAOTONG UNIV

Wireless measuring system and measuring method for multi-node resonant surface acoustic wave sensor

The invention discloses a wireless measuring system and measuring method for a multi-node resonant surface acoustic wave sensor. The wireless measuring system is characterized in that corresponding tothe frequency band of each resonant surface acoustic wave sensor, a reader transmitting circuit transmits excitation signals of multiple frequency bands at the same time through a plurality of localoscillation sources to simultaneously measure the resonance frequencies of a plurality of sensors. Moreover, a reader receiving circuit directly performs the band-pass sampling on the amplified and filtered radio frequency echo signals, and then performs frequency-domain interpolation on the Fourier-transformed echo spectrum information. Compared with the conventional reader that measures the resonant frequency of each sensor with a single local oscillation source by polling, the measurement real-timeness is greatly improved, and the measurement precision is improved by a frequency-domain interpolation method. Besides, because the reader receiving circuit adopts the direct band-pass sampling method of the radio frequency signal, the down-conversion circuit is not needed, not only the structure is simple and the cost is low, but also the signal-to-noise ratio is improved.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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