4525 results about "Measuring instrument" patented technology

The invention discloses an indoor water tank sediment starting speed measurement system and method, and aims to solve the technical problem that data accuracy is affected due to the fact that a sensor disturbs a flow field in an existing measurement method. The core of the technical scheme is that the non-contact measurement characteristic of the PIV technology is applied to the whole process from flow field construction to data acquisition. The device is mainly composed of an imaging unit, a laser lighting unit, a movable sliding frame, a water flow adjusting unit and a buffer plate. Optical measurement is carried out through the imaging unit and the laser illumination unit, a physical sensor does not need to be arranged in a flow field, and interference of a measuring instrument on a water flow structure and a sediment starting process is fundamentally avoided. The movable sliding frame which is integrally designed integrates the functions of sediment laying, particle throwing and measuring, so that a test area can be quickly positioned; and the buffer plate and the water inlet and drainage adjusting unit are combined, so that a gradually-changed flow field from weak to strong can be accurately and stably simulated.

The invention relates to the technical field of laser measuring equipment, and discloses laser length measuring equipment for caution light production, which comprises a supporting seat, a rotating table rotationally mounted at the top end of the supporting seat, a laser measuring instrument arranged above the rotating table and a plurality of fixing assemblies arranged on the rotating table, a driving mechanism for driving the rotating table to rotate is arranged on the rotating table; through meshing arrangement of a first bevel gear and a second bevel gear in the synchronous driving assembly and a threaded transmission structure of a driving screw rod and a sliding block, synchronous movement of a clamping plate driven by a plurality of vertical plates is achieved, it is ensured that a warning lamp cover is accurately positioned to the axis position of the detection table, and the detection efficiency is improved. Therefore, the laser measuring instrument can accurately irradiate the center position of the top end of the lampshade, the problem of large measurement data deviation caused by insufficient positioning precision in the prior art is effectively solved, and the detection precision is remarkably improved.

The invention relates to the technical field of electrical measurement, and discloses an electrical measurement instrument dynamic calibration error compensation method, which comprises the following steps: S1, multi-source data real-time acquisition: integrating a temperature sensor, a humidity sensor and an electromagnetic interference detection module in a measurement instrument, configuring voltage, current, frequency and other measurement channels, and carrying out multi-source data real-time acquisition at the frequency of not less than 100HZ; environmental parameters (temperature T, humidity H and electromagnetic interference intensity E) and measurement data (model characteristic parameters X1, X2,..., Xn such as voltage, current and frequency) are synchronously acquired. According to the electrical measuring instrument dynamic calibration error compensation method, through multi-source data real-time acquisition and composite error model construction, in combination with multiple linear regression and an improved BP neural network, environment and measurement signal changes are comprehensively captured, an error compensation value is accurately calculated, a measurement error can be effectively controlled within an extremely small range, and the error compensation accuracy is improved. Compared with a traditional method, the measurement precision is greatly improved.

A test and / or measurement instrument includes at least three ports and at least three measurement circuits connected to the at least three ports, respectively. The test and / or measurement instrument further includes at least one signal generator circuit and a control circuit. The control circuit is configured to set a first calibration mode and carry out a first test of the instrument by measuring the calibration signal travelling from the signal generator circuit to the respective port as well as a signal traveling from the respective port to the signal generator circuit. The control circuit is configured to set a second calibration mode and carry out a second test of the instrument by measuring the calibration signal forwarded only to the main port in the first sub-mode and the calibration signal received by the respective port from the signal generator circuit via the main port in the first sub-mode.

The invention belongs to the technical field of three-coordinate measuring instruments, and particularly relates to a gear three-coordinate measuring instrument which comprises a measuring table, a Y-axis guide rail is installed on one side of the upper end face of the measuring table, a first displacement frame is arranged on the Y-axis guide rail in a sliding mode, an X-axis guide rail is installed on one side of the first displacement frame, and a sliding block is arranged on the X-axis guide rail in a sliding mode. A Z-axis guide rail is installed on one side of the sliding block, a lifting rod is arranged on the Z-axis guide rail in a sliding mode, and a rotating column is rotationally arranged at one end of the lifting rod. By means of the adjustable gear feeding assembly, continuous feeding and measurement of a plurality of gears are achieved. According to the assembly, before the electric clamping jaw conducts clamping, the gears which are originally stacked in a mess are arranged in an ordered state, so that the electric clamping jaw can conduct accurate clamping only by running according to a preset track, and clamping difficulty and errors caused by mess gear stacking are effectively avoided.

The invention discloses a measuring instrument for measuring the roundness of an inner ring and an outer ring of an automobile hub bearing, and particularly relates to the field of bearing roundness measurement, the measuring instrument comprises a working table, a rotating disc is arranged on the upper surface of the middle of the working table, an adsorption cavity is embedded in the surface of the middle of the working table, and air holes are formed in the surface of the rotating disc; a driving gear is fixedly connected to the outer wall of the middle of the driving shaft, a blade fan shaft is arranged on one side of the inner wall of the adsorption cavity through a bearing, a blade fan gear is fixedly connected to the outer wall of the middle of the blade fan shaft, a spiral blade fan is fixedly connected to the outer wall of the top of the blade fan shaft, and a measurement supporting assembly is arranged on one side of the rotating disc. An auxiliary adjusting assembly is arranged on the side, away from the measurement supporting assembly, of the rotating disc. According to the device, the spiral blade fan can be automatically driven to rotate through the rotation of the rotating disc, so that the workpiece is adsorbed, no mechanical clamping trace exists, the hub bearing workpiece is fixed through the assistance of adsorption force, and the detection stability is improved.

The invention discloses a multi-discharge efficient precision machining device and method for a milling cutter. The multi-discharge efficient precision machining device comprises a high-precision machining tool, an electric spark machining pulse power supply, a discharge monitoring device and a detection device. The high-precision machining machine tool comprises an electric spark machining machine tool, a spindle, a grinding wheel, a workbench and a machine tool body. The main shaft supports accurate movement in three directions; stable and controllable pulse current and voltage are output through the electric spark machining pulse power supply; a voltage probe and a current probe are arranged on the discharge monitoring device, and discharge voltage and current data are collected in real time through the voltage probe and the current probe; the detection device comprises a non-contact optical measuring instrument, the abrasion of the grinding wheel is monitored through the non-contact optical measuring instrument, meanwhile, the machining allowance of the milling cutter blank placed on the workbench and the size precision after finish machining are measured, and the surface quality of the milling cutter is detected; the machining precision and efficiency of the milling cutter are improved, and efficient precision machining of the milling cutter is achieved.

The invention discloses a roll gap measuring instrument and an integrated continuous casting machine online roll gap measuring device, and aims to improve the precision of roll gap measurement and the convenience of operation. The roll gap measuring instrument comprises a mounting frame and a measuring assembly. The measuring assembly comprises a swing arm, a first elastic piece, a shifting block, a detection piece and a first detector. The swing arm is rotationally connected with the mounting frame, the shifting block is connected with the swing arm, and meshing teeth are arranged on the shifting block. The first detector is installed on the installation frame, the detection piece is in sliding fit with the first detector, and a rack meshed with the meshing teeth is arranged on the detection piece. The first elastic piece is used for driving the detection piece to return to the initial position. When the swing arm drives the shifting block to rotate, the shifting block drives the detection piece to move, the swing amplitude of the swing arm is calculated according to the moving distance of the detection piece, and then the roller gap between the rollers to be measured is obtained. According to the roll gap measuring instrument, through cooperation of the swing arm, the shifting block, the detection piece and the first detector, high-precision measurement of the roll gap is achieved, and the accuracy and reliability of a measurement result are improved.

The invention discloses an indoor water tank sediment pushing characteristic acquisition system and method, the system mainly comprises a water tank main body, a buffer unit, a drainage adjusting unit, a sediment throwing device, an imaging unit, an adjustable support and a data processing unit, and according to the method, non-contact data acquisition is carried out through a high-definition camera and a three-dimensional terrain measuring instrument; automatic identification, parameter extraction and migration speed calculation of landforms such as sand waves are achieved, the sediment bed surface is not touched in the whole process, damage to the bed surface form caused by traditional contact type measurement is eliminated, and the authenticity and reliability of data are ensured. Meanwhile, the buffer design of the combination of the flow slowing plate and the multi-stage water baffle is adopted, the kinetic energy of water flow is effectively dissipated through the graded water outlet structure, the impact force of injected water flow is greatly reduced, the bed surface is prevented from being scoured in the initial water injection stage, and the stability of the initial test condition is powerfully protected.

The present invention is a parameter estimation method for compartment model based on physics-informed neural networks. Starting from a physical model, the method extracts information from an AIF and a small amount of measurement data to obtain kinetic parameters, thereby greatly improving the scanning efficiency of a measuring instrument, and reducing occurrence of inaccurate estimation results due to patient movement. In addition, the present invention has the robustness to AIF noise and measurement data noise, and can flexibly arrange the time of data acquisition, reduce an error of inaccurate estimation caused by long time 10 acquisition and the patient movement, and improve the efficiency of data acquisition of the instrument. Experimental results show that the present invention is more stable and has less errors. Meanwhile, the present invention does not require the setup of training datasets, and is superior to an end-to-end supervised reconstruction method U-net network with fewer samples.

A method for surveying an environment by a movable surveying instrument with a progressional capturing of 2D-images by at least one camera and applying a visual simultaneous location and mapping algorithm (VSLAM) or a visual inertial simultaneous location and mapping algorithm (VISLAM) with a progressional deriving of a sparse evolving point cloud of at least part of the environment, and a progressional deriving of a trajectory of movement. The method comprises a progressional matching of the sparse evolving point cloud with a previously derived 3D-geometry, with a minimizing of a function configured to model a distance between the sparse point cloud and the previously derived 3D-geometry and deriving a spatial localization and orientation of the surveying instrument. At least one surveying measurement value of the environment by a spatial measurement unit is combined with the sparse point cloud or the previously derived 3D-geometry.

The invention provides a laser, inertia and image recognition combined calibration method and system. Comprising the following steps: setting a parameter calibration checkerboard on a marble platform for detection, and leveling the parameter calibration checkerboard; carrying out inertial navigation IMU static parameter calibration and inertial navigation IMU dynamic parameter calibration on the inertial navigation IMU, and correcting an inertial navigation IMU error; irradiating laser spots of a laser into the parameter calibration checkerboard, shooting the parameter calibration checkerboard from different angles through a machine vision camera, and obtaining a parameter calibration checkerboard photo set; and joint calibration of parameters of a machine vision camera, an inertial navigation IMU and a laser is carried out, and automatic correction of external parameters of various precise positioning measuring instruments and high-precision measurement of local space are realized.

The invention discloses a measuring instrument automatic calibration method and system based on big data, and the method comprises the steps: obtaining the multi-dimensional operation data of a measuring instrument in real time through a sensor, and covering the equipment state and environment parameters; processing the data to generate an operation data set, and extracting a fluctuation characteristic value of the quantitative state change by adopting time sequence analysis; when the fluctuation characteristic value exceeds a preset threshold value, triggering depth characteristic decomposition to obtain deviation distribution information; on the basis of the information and in combination with historical records, the optimal calibration opportunity is judged through a machine learning model; and a calibration instruction is automatically generated and issued to the instrument control module to execute calibration. According to the method, the defects that traditional calibration depends on manpower and is not accurate in time are overcome, intelligent and automatic calibration based on the real state is achieved, the calibration precision and efficiency are remarkably improved, and the adaptability and robustness of the system in the complex environment are enhanced.

The invention belongs to the technical field of flow instruments, and provides a dynamic compensation and error correction system of a high-precision flow instrument, which comprises a multi-dimensional data acquisition and preprocessing module, a module capable of being additionally provided with a sensor, a module for establishing a data stream with a timestamp and processing data, a module for fluid network modeling and priori knowledge construction, and a data processing module. A distributed collaborative optimization and parameter calibration module capable of constructing a directed graph model and generating initial compensation parameters; a network association reasoning and dynamic weight distribution module capable of adding a global penalty term to optimize parameters on the basis of a traditional error function; a working condition adaptation calibration and cross-domain parameter migration module capable of constructing an association graph, detecting abnormity and distributing weights; real-object-free calibration and parameter migration can be realized; according to the system, through multi-module cooperation, the problem that traditional single-table compensation is local and is not global is solved, and high precision and real-time performance of industrial-grade cooperative metering are supported.

The utility model provides a difunctional angle measuring instrument, which relates to the technical field of angle measuring instruments, and comprises a first graduated scale, one side of the first graduated scale is fixedly connected with a circular shaft, the outer ring of the circular shaft is rotatably connected with a second graduated scale, one side of the second graduated scale is provided with a first sliding chute, and the second graduated scale is provided with a second sliding chute. A first sliding groove is formed in one side of the first graduated scale, a second sliding groove is formed in the other side of the second graduated scale, angle scale marks are arranged on one side of the second graduated scale, a pointer is fixedly connected to one side of the first graduated scale, and one end of the pointer penetrates through the first sliding groove and points to the angle scale marks. Therefore, the rotating angle of the arc-shaped rack driven by the rotating gear is small, so that the effect of accurately adjusting the second graduated scale is achieved, the situation that the force is too large or too small during operation can be avoided, the measurement accuracy is improved, the angle measuring instrument is convenient to use, and the use effect is improved.

The invention relates to the technical field of measuring devices, in particular to a glass thickness measuring instrument which comprises a workbench, the upper end of the workbench is fixedly connected with a first support, the upper end of the first support is provided with a first motor, and the lower end of the first support is provided with a first detection mechanism used for detecting an arc-shaped curved glass plate in a contact mode. A contact type laser micrometer is installed on the inner side of the first detection mechanism, a second detection mechanism used for non-contact type laser scanning detection of a glass plate is arranged on the inner side of the first detection mechanism, a plurality of sets of anti-reflection laser triangular sensors are arranged on the inner side of the second detection mechanism, and the anti-reflection laser triangular sensors are arranged on the inner side of the second detection mechanism for laser reflection interference caused by an arc-shaped curved surface. The anti-reflection laser triangular sensor is matched with the conical black velvet inner wall of the refraction plate and the 45-degree light barrier array to form an efficient optical trap, scattered light and transmission echoes are thoroughly absorbed, and the device is particularly suitable for high-precision measurement of high-power laser of 100 mW or above under an arc curved surface.

The utility model provides an on-line rotary viscometer, which belongs to the technical field of viscosity measuring instruments and comprises a measuring chamber, a rotor, a stator, a driving component and a detecting piece, and the measuring chamber is suitable for being communicated with a pipeline to be measured; the rotor is arranged in the measuring chamber, the rotor is of a cylinder structure with a cavity inside, and a plurality of liquid inlet grooves communicated with the cavity are formed in the side wall of the rotor; the stator is rotatably arranged in the cavity, and a medium channel is arranged between the stator and the rotor; the driving assembly is connected with the rotor, a medium flowing through the medium channel can rotate around the stator under the rotating action of the rotor, and the rotating medium can drive the stator to rotate or drive the stator to generate a rotating trend; the detection piece detects the viscous torque borne by the stator during rotation. According to the online rotary viscometer provided by the utility model, the rotation of the stator is driven by a medium without friction loss caused by a transmission process, so that the viscous torque during the rotation of the stator is accurately obtained, and the accuracy of a result is improved.

The invention relates to the technical field of rubber cloth thickness measurement, and discloses a rubber cloth laser thickness gauge and method, and the rubber cloth laser thickness gauge comprises a supporting frame, the top of the supporting frame is provided with a conveying mechanism, one side of the conveying mechanism is provided with a transmission mechanism, the exterior of the transmission mechanism is provided with a cleaning mechanism, and the top of the supporting frame is provided with a detection mechanism. The cleaning mechanism is arranged on one side of the detecting mechanism, a collecting mechanism is arranged on one side of the supporting frame, a marking mechanism is arranged on one side of the collecting mechanism, the conveying mechanism comprises a first motor, the outer portion of the first motor is arranged on the top of the supporting frame, and the output end of the first motor is fixedly connected with a first driving gear. The rotating rod is in linkage with the belt wheel and the rotating disc structure, the protruding block is driven to periodically compress the piston assembly to form air pressure pulses, air flow is exhausted through the air outlet pipeline to sweep the surface of rubber cloth, and therefore the technical effect of synchronously cleaning the surface of the rubber cloth is achieved through the air pressure pulse purging structure.

A value traceability method for an involute curve with a large base circle radius. The method comprises the following steps: step 1, determining a coordinate system for value traceability and value transfer parameters; step 2, adjusting the pose of an involute template (8); step 3, adjusting the position of the involute template (8); step 4, calibrating involute parameters; and step 5, eliminating coordinate system establishment errors to achieve calibration of a measurement instrument. The method fills the gap of value traceability methods for large-size gears with diameters greater than 500 mm, and can effectively identify the impact of coordinate system establishment errors on the accuracy of tooth profile measurement, and improve the applicability of a large-gear measurement instrument (9) in complex environments such as on-machine measurement. The method enables high-precision involute measurement, is simple and easy to implement, offers high measurement accuracy, facilitates transportation and installation adjustments, and has good market application prospects and promotion value.

The utility model discloses a pumping type multi-parameter measuring device, which comprises a main shell, a passive ventilation device, a gas detection unit, a suction device, a power supply and a controller, and is characterized in that the main shell comprises a diffusion cavity, a communication cavity, a detection cavity and a control cavity which are communicated in sequence; the passive ventilation device is rotatably arranged in the diffusion cavity, an angular velocity sensor is arranged on the passive ventilation device, and the multiple gas detection units are all arranged in the detection cavity; the suction device, the power supply and the controller are all arranged in the control cavity, and the suction device is communicated with the detection cavity; the suction device and the angular velocity sensor are respectively connected with the controller; the power supply is electrically connected with the suction device, the angular velocity sensor and the controller, so that the accuracy and the efficiency of pump suction type sampling in a quiet wind or breeze environment are ensured, detection can be carried out by utilizing a natural diffusion principle when external wind power is enough, and unnecessary energy consumption is reduced.

The utility model relates to the technical field of fluid flow measuring instruments, in particular to a vortex shedding flowmeter which comprises a measuring tube, a generating body embedded in the measuring tube, a sensor arranged on one side of the generating body and a meter head arranged above the sensor. An insertion groove and a fixing groove are sequentially formed in the two sides of the measuring pipe in the direction away from the middle of the measuring pipe respectively, the fixing groove and the insertion groove are each of an annular groove-shaped structure, one end of the fixing groove is communicated with the insertion groove, the other end of the fixing groove is located on the end face of the measuring pipe, and a fixing ring is arranged in the fixing groove in a sleeved mode; the outer diameter of the fixing ring is matched with the groove diameter of the fixing groove, an inner cavity of the fixing ring is of a conical structure, the diameter of the inner cavity of the fixing ring is gradually decreased in the direction close to the inserting groove, a fixing ring made of elastic materials is sleeved with the fixing ring, and the outer structure of the fixing ring is matched with the structure of the inner cavity in the middle of the fixing ring. The vortex shedding flowmeter is good in sealing effect and accurate in measurement result.

A test system has ovens configured to hold devices under test (DUTs), DUT switches, each connected to the DUTs in an oven, splitters, each splitter connected to a DUT switch, an instrument switch connected to one output of each splitter, the other output of each splitter connected to a test instrument, and one or more processors to control the instrument switch to select one of the DUT switches connected to an oven, control the selected DUT switch to connect each DUT in the oven to a channel of the test and measurement instrument, use machine learning to tune the DUT to a set of parameters until the DUT passes or fails, repeat the connecting, tuning, and testing of each DUT until all DUTs in an oven have been tested, and repeat the selection and control of the DUT switches until each DUT in each oven has been tuned and tested.

The utility model relates to the technical field of housing construction engineering, and discloses a housing construction engineering positioning and measuring device which comprises a supporting table, a supporting rod is movably connected in the supporting table in a penetrating mode, a measuring instrument is fixedly connected to the upper end of the supporting rod, and a supporting mechanism is arranged on the lower surface of the supporting table. A rack is fixedly connected to the left side surface of the supporting rod, and an adjusting mechanism is arranged on the upper surface of the supporting table and located on the left side of the supporting rod. According to the utility model, in the aspect of height adjustment, through the linkage design of the supporting rod and the rack and the combination of a mechanical locking mechanism of the gear, the ratchet wheel and the pawl, stepless precise adjustment of the measuring instrument is realized, and the motor fault risk and power consumption are avoided; in addition, the rotating rod can be locked through the positioning bolt after adjustment is completed, accidental displacement of the measuring instrument is prevented, and the reliability of the device is further improved. According to the design, through a pure mechanical structure, the height adjusting process is simplified, the maintenance cost is reduced, and the device is particularly suitable for engineering scenes in a power-free environment.

The invention discloses a filter tip modeling parameter visual identification and adjustment method, and relates to the technical field of filter tip production, a laser diameter measuring instrument and a linear array camera are used for synchronously collecting peripheral images of a filter tip, and high-precision and consistent size and gray scale double baselines are generated; a texture segmentation technology is adopted to identify a suspected recess area and generate a recess position vector, a confocal displacement sensor is utilized to carry out local depth walk-up to obtain depth distribution data, and a size compensation coefficient is generated and a size matrix is corrected through Gaussian process regression; statistical threshold analysis is conducted on the corrected size matrix, when parameters exceed the limit, the gap of a forming nozzle is adjusted, the size stability of the filter tip is ensured, the adjustment result and related data are written into a manufacturing knowledge base, follow-up batch optimization is supported, and the measurement reliability and the production line efficiency are improved; tiny recesses on the surface of the filter tip can be effectively identified and compensated, and the measurement accuracy and the assembly stability of modeling parameters are ensured.

The invention relates to the technical field of steel template detection equipment, and discloses a surface flatness detection device based on steel template production, which comprises a detection table, two mounting seats are fixedly mounted at the top of the detection table, driving gears are movably connected to the middle sides of the interiors of the mounting seats through bearings, and two guide rails are mounted at the tops of the mounting seats. Two connecting plates are slidably connected outside the guide rail, a telescopic rod is mounted at the top of the mounting seat, a driving rack is mounted on the outer side of the mounting seat, and the telescopic end of the telescopic rod is fixedly connected with the outer sides of the connecting plates. According to the invention, stable and accurate clamping of steel templates with different shapes and sizes is realized, the device can effectively adapt to steel templates with different specifications, frequent clamp replacement or complex adjustment is not needed, the universality and flexibility of detection are greatly improved, the device is matched with a high-precision optical flatness measuring instrument, non-contact measurement can be carried out on the surface of the steel template, and the detection precision is improved. And the accuracy and the reliability of a measurement result are ensured.

The invention relates to a multi-meter-position water meter calibrating device, and relates to the field of metering instrument calibration, the multi-meter-position water meter calibrating device comprises a waterway circulation module, a water meter clamping module, a sealed calibration module, a flow detection module and a water quantity metering module, the waterway circulation module can drive calibration water to circularly flow in a circulation pipeline, and the water meter clamping module comprises a plurality of meter positions to be calibrated; the plurality of meter positions to be detected are arranged on the circulating pipeline in series, the sealed detection module is connected with the water meter clamping module, the flow detection module and the water quantity metering module are respectively arranged on the circulating pipeline, the flow detection module comprises a plurality of flow meters, scale grids of the plurality of flow meters are different, one of the plurality of flow meters is selected to be connected on the circulating pipeline, and the water quantity metering module is connected with the water meter clamping module. The water quantity metering module comprises a plurality of water quantity meters, the scale grids of the water quantity meters are different, one of the water quantity meters is selected to be connected to the circulating pipeline, and the water meter verification accuracy and verification efficiency can be improved.

The invention discloses a surface roughness and size precision common prediction method based on a relative position matrix, and mainly relates to the field of roughness detection. Comprising the steps that in the turning machining process, vibration signals are collected in real time through multi-channel acceleration sensors arranged at the positions of a main shaft, a tool and a workpiece clamp, and a roughness measuring instrument and a micrometer are synchronously used for measuring the surface roughness value and size data of a machined workpiece; normalization processing is carried out on the collected vibration signals, the vibration signals are converted into two-dimensional images to be expressed based on a relative position matrix algorithm, deep features are extracted through two-dimensional discrete wavelet transform, and the spatial expression ability of the signals is enhanced. The method has the beneficial effects that the vibration signal is converted into the two-dimensional RPM graph through the RPM, and the 2D-DWT is utilized to perform decomposition reconstruction and image fusion, so that the deep sharing features in the vibration signal are effectively extracted, and the method plays a key role in improving the prediction precision of the surface roughness and the size precision.

The invention provides a device and method for measuring the flow velocity and flow of gas in a pipeline, and particularly relates to the technical field of measuring instruments, and the device comprises a flow field optimization assembly, a flow velocity sensing assembly and a signal processing assembly. The flow field optimization assembly comprises a plurality of air duct partition plates and straight pipe sections, and the gas conveying pipeline is divided into a plurality of independent divided air ducts; the flow velocity sensing assembly comprises a rectification assembly and a pressure sensing assembly, the rectification assembly comprises a pore plate and / or a grid, and the pressure sensing assembly comprises a plurality of uniformly distributed pressure sensing elements; the signal processing assembly comprises a differential pressure sensing transmitter, a static pressure sensing transmitter, a temperature sensing transmitter, an atmospheric pressure sensing transmitter and a data processing module. The pressure sensing element detects differential pressure signals, the differential pressure sensing transmitter converts the signals, the data processing module calculates the average flow velocity and flow of gas based on the signals and measurement data, and the measurement precision and accuracy are improved.

The invention relates to the technical field of high-precision optical detection, in particular to a fixing assembly for installing a lens measuring instrument and the measuring instrument, and the fixing assembly comprises a rooting block which is used for being connected to the back surface of a lens in a gluing manner; the base is connected with the rooting block through a fastening assembly, the base is provided with at least three first contacts opposite to the back face of the lens and at least two second contacts opposite to the side face of the lens, and the fastening assembly is configured to be capable of generating first elastic force on the base in the first direction; and a second elastic force in a second direction. The rooting block is adhered to the back surface of the lens, so that a mechanical attachment point is prevented from being found on a vulnerable optical surface; meanwhile, the base is elastically connected with the rooting block through the fastening assembly instead of being rigidly and directly fixed, and the base elastically abuts against the back face and the side face of the lens through the first contact and the second contact respectively, so that self-adaptive accurate positioning of the base with the mirror face as the benchmark is achieved.

The invention discloses a rapid butt-joint positioning method for a hyperbolic arc-shaped steel beam, belongs to the technical field of steel structure building construction, and mainly aims to solve the problems of high butt-joint positioning difficulty, low precision, poor efficiency and high safety risk of the hyperbolic arc-shaped steel beam in high-altitude assembly installation. The temporary connecting plate with the spherical hinge joint and the annular positioning boss and the temporary connecting base with the spherical hinge nest and the annular positioning groove are welded to the end of the steel beam, a measuring instrument is used for obtaining the coordinate of the mark point and fitting deviation, and the steel beam is controlled to descend stably through synchronous hoisting, active swing restraining, adjustable supporting and a real-time monitoring system. And after preset position deviation and weight transfer rate threshold values are reached, the horizontal position is finely adjusted, so that the spherical hinge head sinks into the spherical hinge nest, the annular positioning boss is embedded into the annular positioning groove, and finally fastening is completed by adopting a conical centering pin rod and a bolt. By means of the method, high-precision, high-efficiency, safe and reliable butt joint of the hyperbolic arc-shaped steel beams is achieved.