211 results about "Protractor" patented technology

The utility model relates to the technical field of steel structure measurement, and discloses a super high-rise steel structure measuring device, which comprises an angle measuring ruler and two angle measuring rods, one ends of the two angle measuring rods are rotationally connected to the middle part of the angle measuring ruler; the bottom of the protractor is connected with a fixing rod, the fixing rod is slidably sleeved with an adjusting piece used for adjusting the angle between the two protractor rods, and the adjusting piece is provided with an elastic pressing piece abutting against the fixing rod. One end, far away from the protractor, of the fixed rod is provided with a rod type driving piece for adjusting the length of the fixed rod; a telescopic piece used for pushing the adjusting piece to slide on the fixing rod is installed on the adjusting piece. The utility model provides a super high-rise steel structure measuring device, which solves the problem that when an equivalent angle rod is in contact with a steel structure, the surface of the steel structure is uneven or misoperation occurs, and the angle measuring rod is easy to rotate, so that the measured angle is deviated.

The utility model relates to the technical field of geological exploration measuring tools, in particular to an inclination angle measuring device for geological exploration, which comprises a main body frame, one end of the main body frame is connected with an adjusting structure in a sliding manner, and the adjusting structure comprises an adjusting frame body and a positioning part which is in threaded connection with the adjusting frame body; a plurality of positioning holes are formed in the adjusting frame body, and the positioning parts selectively penetrate through the positioning holes and penetrate into the ground; and the other end of the main body frame is rotationally connected with a measuring plate and a protractor. Through the matching design of the adjusting frame body and the positioning part, the positioning part penetrates into the ground inside and outside the main body frame, so that the device can be better fixed with the ground, and the stability in the measurement process is improved. And the adjusting frame body is designed in a sliding connection mode, so that the position and height of the device can be quickly adjusted. Meanwhile, due to the storage design of the positioning part, the device is more compact in a non-measurement state and is convenient to carry.

A portable multipurpose subdivision graduation protractor comprises a main ruler, an auxiliary ruler and a precise hinge shaft unit. The main ruler is of a structure similar to a right triangle, two right-angle sides are main ruler arms, a bevel edge is replaced by a 135-degree fold line, and 45-degree, 135-degree and 90-degree external angles are provided and can be directly used as a fixed angle sample plate; the surface of the main ruler is provided with easily-identified fan-shaped distribution scales which are correspondingly arranged in two layers as difference reference lines; parallel step notches are formed in the upper edge of the vertical main ruler arm and are used for small-angle measurement; the auxiliary ruler is of a two-right-angle-side structure, the vertical side is an auxiliary ruler arm, and the auxiliary ruler can also be used as a fixed-angle sample plate. The horizontal side is a pointer arm, the end portion is of a fan-shaped structure, the radius is the same as that of the fan shape of the main ruler, and ruler reading visual errors can be reduced. Various interior angles can be widely measured and mapped, difference group scribed lines are effectively set, and an error conduction chain is shortened due to the fact that the whole ruler is not provided with redundant components. The precision machining problem is solved, and the measurement precision can be further improved.

The utility model relates to the technical field of measuring devices, and discloses a foldable measuring device for building design, which comprises a first ruler strip and a second ruler strip which are rotatably connected, the lower part of the front end of the first ruler strip and the upper part of the front end of the second ruler strip are both provided with scale marks, the upper part of the rear end of the first ruler strip is provided with a first groove, and a second groove is formed in the rear end of the second ruler strip. The lower portion of the front end of the second ruler strip is provided with a second groove which is the same as the first groove in size, the upper portion of the first ruler strip is provided with a sliding groove, the front end of the first ruler strip is detachably connected with a protractor, a sliding block of an inverted-T-shaped structure is arranged in the first groove in a sliding mode, and the front end of the sliding block penetrates through the sliding groove and then is connected to the protractor. The angle between the first ruler strip and the second ruler strip can be adjusted, and the protractor can be detachably installed on the first ruler strip to measure the upward angle through cooperation of the sliding block, the second lead screw and the second fastening knob. The device is simple in structure, convenient to use, easy to store and high in practicability.

1. The name of the design product: teaching demonstration protractor. 2. The use of the design product: angle teaching demonstration and angle measurement. 3. The design points of the design product: in shape. 4. The picture or photo that best shows the design points: perspective view. 5. Other circumstances that need to be explained: the moving ruler of the design product can be rotated by 90° along the vertex, and the arc scale can be folded up and down, forming the unfolded state and the closed state of the product.

The utility model relates to the technical field of optical measurement, and discloses a laser angle measuring tree height measuring instrument which comprises a scale base, a measuring mechanism is installed on the top of the scale base and used for detection and measurement, and a plurality of telescopic mechanisms are installed on the front side and the rear side of the bottom of the scale base at equal intervals. The telescopic mechanism is used for adjusting the height of the scale base; the measuring mechanism comprises a fixed short piece, the fixed short piece is installed on the top of the scale base, a supporting column is fixedly connected to the middle of the inner wall of the fixed short piece, and an arc-shaped support is fixedly connected to the top end of the supporting column. According to the utility model, the laser pen aims at the top of a tree, and the electronic protractor measures an angle alpha; the measuring mechanism is moved to the left inserting groove, the angle beta is measured after leveling, the distance L between two points of the scale of the base is read, the tree height is calculated through a formula, the instrument is made of a laser pen and an electronic protractor which are common objects, the cost is smaller than 100 yuan, operation is easy and convenient, and the instrument is worthy of popularization.

This utility model discloses a mortise and tenon joint type police metal badge, including a metal badge body and a metal badge structure set at the front side; a protractor is set in the side groove, and a central connecting shaft is set at the middle of the end of the protractor; a side telescopic blade is set inside the metal badge body, and a length value is set on the side telescopic blade; a toggle block is set on the side of the side telescopic blade, and a limit moving groove is set on the outer side of the toggle block; by pushing and pulling the toggle block, the side telescopic blade can be extended and retracted; the protractor can be rotated to the outside for angle measurement or to the inside for concealment via the central connecting shaft. After the improvement of this utility model, some simple measuring tools can be integrated into the badge, which can provide preliminary reference data in emergency situations, thereby effectively improving the practicality of the police metal badge.

The utility model discloses a drainage tube fixing device capable of measuring the lifting angle of a bedside, which belongs to the field of medical instruments and comprises a protractor and a ruler strip, the back of the protractor is fixedly connected with a bed board fixing component, the front of the protractor is provided with a sliding groove, and the protractor is movably connected with the ruler strip through a movable shaft. The bottom end of the ruler strip is fixedly connected with the protractor through a locking bolt, and the top end of the ruler strip is fixedly connected with a gradienter; according to the drainage tube fixing device capable of measuring the lifting angle of the bed head, by arranging the protractor, the sliding groove, the ruler strip, the movable shaft, the locking bolt, the gradienter, the movable sleeve, the fixator and the laser lamp, measurement of the lifting angle of the bed head and measurement of the hanging height of the drainage tube can be integrated in the hanging process of the drainage tube; medical staff can conveniently, quickly and accurately find the fixed height of the drainage tube and the lifting angle of the bed head, so that convenience is brought to the work of the medical staff.

The utility model relates to the technical field of measuring tools, in particular to a measuring tool for detecting the bending angle of a floor reinforcing steel bar. Comprising a protractor, a fixed ruler fixedly connected to one side of the protractor and extending in the radial direction of the protractor, a movable ruler rotationally connected to the circle center of the protractor and extending in the radial direction of the protractor, and a locking assembly arranged at the circle center of the protractor and used for jointly locking or unlocking the protractor and the movable ruler. And the positioning devices are respectively arranged on the back surfaces of the fixed ruler and the movable ruler and can be fixed on a reinforcing steel bar. The measuring tool is simple in structure, convenient to operate, small in starting difficulty and not prone to being influenced by the proficiency of workers, and the accuracy of steel bar bending angle measurement is greatly improved.

This utility model belongs to the field of lathe tool measurement technology, and in particular to a vertical lathe tool measuring device, including a first vertical support frame, a base plate, and a second vertical support frame. Its features include: a protractor slidably connected to one side of the second vertical support frame; a horizontal rod fixedly connected to one side of the protractor; a movable plate provided on one side of the protractor; a limiter detachably connected to one side of the horizontal rod; connecting blocks provided on both sides of the movable plate; the horizontal rod passing through one of the connecting blocks; and the horizontal rod being fixedly connected to an adjacent connecting block. Before machining, the device measures the tool according to different shape machining requirements, selects a suitable tool, and measures the angle of tools used for a period of time, filtering out tools with high wear and replacing them to avoid large errors during machining caused by excessively worn tools, thereby ensuring product quality.

The invention discloses a puncture auxiliary device, and particularly relates to the technical field of medical instruments. The puncture auxiliary device comprises a protractor, an arc-shaped groove is formed in the protractor, and the distance between the center line of the arc-shaped groove and the circle center of the protractor is a preset value h; the scaleplate is movably installed on the protractor and is perpendicular to the bottom side plane of the protractor, the scaleplate can move along the arc-shaped groove, and a calibration line used for indicating an angle is arranged at the end, close to the protractor, of the scaleplate; the scale is sleeved with the moving assembly in a sliding mode, the moving assembly comprises a limiting component used for limiting a puncture needle, and a limiting hole used for limiting the puncture needle is formed in the limiting component. The device is simple in structure and convenient to operate, can realize single-person accurate puncture, effectively solves the problems of low efficiency and large error of multi-person manual measurement for avoiding ribs in a traditional method, and remarkably improves the safety and success rate of inclined puncture.

The multifunctional woodworking ruler comprises a first main body, a second main body, a protractor and a positioning assembly, and the first main body is provided with a first straight line edge and a second side edge; the second main body is provided with a first side edge and a second straight edge; the protractor is mounted on the first main body; the first main body and the second main body are rotatably connected; the second main body is provided with a groove body for accommodating the protractor; the first main body and the second main body can relatively rotate to a closing position and a maximum opening position, and at the closing position, the protractor is accommodated in the groove body; at the maximum opening position, the protractor is pulled out of the groove body; the second body is provided with a positioning assembly acting on the protractor. The multifunctional woodworking ruler has the functions of measurement, line drawing, angle measurement, levelness measurement and the like, the use requirements of users are met, and too many tools do not need to be carried; the multifunctional woodworking ruler can be used for drawing triangles and parallel lines, measuring angles and the like, the structure is compact, the first main body and the second main body can be randomly positioned in a rotatable range, and the measurement is more accurate.

The invention relates to the technical field of interventional therapy, and particularly discloses a percutaneous puncture navigation system which comprises a camera module and a display module, the display module displays a main picture shot by the camera module, and an electronic protractor picture is suspended on the main picture as a floating layer; a puncture layer S, a puncture point A, a puncture angle alpha, a puncture depth D and a puncture target point T of a focus area of a patient are determined, a camera module is arranged on one side of the patient in the scanning direction, and the camera module aims at the body surface of the focus area to shoot, so that a round point O in a picture of the electronic protractor coincides with the puncture point A of the body surface of the patient; a datum line in an electronic protractor picture is parallel to the horizontal plane; the puncture needle coincides with the angle line of the angle alpha in the picture of the electronic protractor, and the puncture needle enters the depth D along the angle line alpha of the electronic protractor and then reaches the puncture target point T. The puncture cloth needle arranged as the puncture needle achieves the visual navigation function, reduces the puncture difficulty, improves the puncture precision and reduces the puncture scanning frequency.

The utility model relates to the technical field of coal mine exploration, in particular to a transient electromagnetic geophysical prospecting line frame rotating device for a coal mine, which comprises two placing rods, a cross rod is fixedly connected to the surfaces of the two placing rods, a protractor is rotatably connected to the side surface of the cross rod, and a rotating shaft is rotatably connected to the side surface of the protractor. A measuring rod is fixedly connected to the surface of the rotating shaft, a rotating plate is fixedly connected to the side face of the measuring rod, a wire frame body is fixedly connected to the side, away from the measuring rod, of the rotating plate, and a limiting device is arranged on the side, away from the wire frame, of the protractor and comprises a half gear. The half gear is fixedly connected to the end, away from the protractor, of the rotating shaft, and a mounting rod is fixedly connected to the side, close to the half gear, of the protractor. According to the utility model, the problem that the accuracy of a measurement result is influenced because the wire frame is often required to be supported by a worker after the angle adjustment of the wire frame is completed and is difficult to ensure that the wire frame does not deflect is solved.

The steel bar bending construction device with the angle measuring function comprises a base and a steel pipe welded to the side face of the base, a to-be-bent steel bar extends out of the steel pipe, and the steel bar bending construction device further comprises a protractor arranged at the end of the base; the spring steel is arranged on the base; the spring steel is provided with the first extending end, and the to-be-bent steel bar part abuts against the spring steel; the arc-shaped groove is formed in the protractor, and the first extending end partially extends out of the arc-shaped groove; the spring steel is provided with a second extending end connecting base; and the first scales are arranged on the protractor. One constructor can bend the to-be-bent steel bar while reading the bending angle of the to-be-bent steel bar in real time, and the bending efficiency is effectively improved. And the influence of rebound of the to-be-bent steel bar on the bending precision is reduced through the compensation value, and the bending precision of the to-be-bent steel bar is effectively improved.

The application provides a ranging device and a casing following rotary drilling hole forming process, and relates to the technical field of ranging equipment. The ranging device comprises a central distance setting mechanism, a support box, a telescopic sleeve and a positioning pipe. The central distance setting mechanism comprises an insertion shaft and a connecting shaft. The top of the connecting shaft penetrates through the support box and is connected with a protractor. A synchronous part is installed in the support box. The synchronous part comprises a synchronous belt, a synchronous slider and two synchronous wheels. The ranging sensor is used to measure the distance between the central axis of the connecting shaft and the outer surface of the positioning pipe. The casing following rotary drilling hole forming process can continue drilling and hole forming until the preset hole depth is reached after the whole casing is installed. The technical scheme provided by the application provides the functions of fast distance setting and point setting for the installation of the calibration rod, and can ensure that the calibration rod maintains a vertical state when it is hammered into the ground, thereby avoiding the problems of deviation and inclination when the calibration rod is hammered.

The utility model discloses a step slope angle rapid measuring device for an open-pit mine, which relates to the technical field of step blasting of open-pit mines and comprises a fixed arm, a protractor, a vertical direction determining piece, an adjusting arm, an infrared laser transmitter and an angle indicating piece. The vertical direction determining piece is arranged on the fixed arm so as to determine that the fixed arm is in a vertical state and enable the bottom edge of the protractor to be in a vertical state, and the adjusting arm is rotationally connected with the protractor and can rotate around the axis of the protractor. The infrared laser emitter is fixedly connected to the end, away from the axis of the protractor, of the adjusting arm so as to emit laser and be positioned to the step slope bottom position, the extension line of the laser penetrates through the axis of the protractor, the angle indicating piece is arranged on the adjusting arm and can indicate the angle when the adjusting arm rotates to the measuring position, the structure is simple, and use is convenient. Use is convenient, and the construction progress is effectively guaranteed.

The utility model discloses an angle gauge, including scale part, alignment amplification part and screw, the scale part includes dial, guide pillar, first pin and nut, the alignment amplification part includes magnifying glass, soft cover, spring, second pin, the dial with guide pillar riveting, the nut with guide pillar riveting, the spring is covered and is established on the second pin, the soft cover is covered and is established on the spring, the second pin is inserted and is established on the magnifying glass, the scale part with alignment amplification part is connected through the nut with screw cooperation, the utility model discloses simple structure can measure or draw geometric figure angle, even close to the geometric figure angle of paper edge, simultaneously, the utility model discloses hand -held convenient, can quickly shift and position.

The invention belongs to the technical field of bent pipe machining, and particularly relates to a steel large-diameter pipeline bent pipe on-site forming method which comprises the steps that the bending angle is measured through a rope and a protractor; the outer perimeter of the pipe is measured by a tape; the bending radius is calculated, and the back height and the belly height of the end joints are calculated according to a given formula; after the steel pipe is horizontally and stably supported, popping up two axial center lines by using the ink box, popping up a bus at equal division points of the circumference, sequentially marking flush opening intersection points of end joints and middle joints according to calculated sizes, and connecting to form a closed cutting line; cutting along a line by using oxygen-propane neutral flame, numbering and assembling, controlling an alignment gap, cutting a V-shaped groove on site, remeasuring the angle by using a protractor after spot welding, correcting distortion, and turning, welding and forming. The bent pipe can be manufactured on the steel pipe feeding and discharging without a material paper sample plate, material paper sample plate manufacturing can be omitted, sample plate errors are avoided, bent pipe manufacturing precision is improved, meanwhile, the method can adapt to the field construction environment, the technology is simplified, rework and material waste are reduced, cost is reduced, and construction efficiency is improved.

The utility model discloses a simple mine angle and gradient measuring instrument, which belongs to the related technical field of mine measurement, and comprises a first base body and a second base body which are rotatably connected, and a main protractor is arranged on the first base body; a round bubble correction device is arranged at the main protractor; a first laser pen and a second laser pen are arranged in the middle of the first base body and the middle of the second base body respectively. A first reading base line and a second reading base line are respectively arranged on the first base body and the second base body; a first side protractor and a second side protractor are arranged in the middle of the first base body and the middle of the second base body respectively, and the first side protractor and the second side protractor are perpendicular to the direction of the main protractor. The utility model provides a simple instrument for measuring angle and gradient of a mine, the problem of larger azimuth measurement deviation caused by magnetic field change can be solved by using the protractor to measure the angle, and the problem of larger gradient measurement error caused by rope bending can be solved by measuring the laser rotation angle.

1. The name of this design product: Protractor (Mathematics). 2. Purpose of this design product: used as a protractor. 3. The key design point of this design product lies in the combination of shape and pattern. 4. The picture or photo that best illustrates the design points: Stereoscopic drawing 1.

The invention relates to the field of medical equipment detection, in particular to an optical lens function inspection device which comprises a device body, the device body comprises a fixing module and a detection module, the fixing module comprises a base, a moving groove is formed in the base, a marking groove is formed in the moving groove, and a fixing assembly is installed at one end of the moving groove and comprises an adjusting rod. The adjusting rod is of a hollow structure. A guide cover is installed at one end of the adjusting rod. The detection module comprises a camera and a mounting frame, a light source and an indexing meter are mounted on the mounting frame, the adjusting rod, the camera, the light source and the indexing meter are mounted on the same axis, the light source is in signal connection with a control module, and the control module is used for controlling the camera to perform sequential shooting on the optical lens to be detected after detecting that the light source is turned on. And the acquired image data is associated and matched with the angle data of the graduator. According to the invention, the convenience, precision and traceability of the detection process are realized, and the use requirements of low cost and easy operation of medical institutions are met.

The utility model provides a device for measuring the offset and deflection angle of a glass substrate, which comprises a positioning frame movably connected to the upper surface of a handle through a main bolt, the upper end and the lower end of the handle are fixedly connected with two groups of positioning plates, and the two ends of the positioning frame are symmetrically provided with through grooves; the top of the through groove is provided with a positioning hole and a buffer groove, an auxiliary bolt is screwed in the positioning hole, a buffer layer is fixedly connected in the buffer groove, the surface of the caliper is correspondingly provided with a guide groove opposite to the position of the auxiliary bolt, the caliper is slidably connected in the through groove through the guide groove, the side face of the clamping groove is symmetrically provided with clamping grooves, and one end of the probe is fixedly connected in the clamping grooves. Through cooperation of the positioning frame, the caliper, the bevel protractor, the handle, the positioning plate, the probe and the probe head, the device can conveniently and correspondingly measure the glass substrate, the probability that the surface of the glass substrate is accidentally damaged due to measurement can be effectively reduced, and the yield of the glass substrate is ensured.

The utility model discloses a protractor convenient to read, which comprises a protractor plate, a central shaft barrel is fixedly arranged in the middle of a transverse plate of the protractor plate, and the middle of the central shaft barrel is hollow. According to the protractor convenient to read, the angle measuring swing sleeve plate is arranged, the angle measuring swing sleeve plate swings by taking the central shaft barrel as a central angle, and the measuring swing needle in the angle measuring swing sleeve plate is aligned to and covers an angle line needing to be measured, so that direct reading can be performed through the reading pointed by the measuring swing needle; the extension ruler sleeve plate is arranged at the other end of the angle measuring swing sleeve plate, and the extension ruler sleeve plate and the extension butt joint ruler plate are spliced for use, so that required line segments are drawn on the right side edges of the extension ruler sleeve plate and the extension butt joint ruler plate by measuring the reading angle of the swing needle; therefore, required angle lines can be drawn quickly and conveniently, and the practicability and accuracy of the protractor are effectively improved.

The utility model discloses an aluminum profile processing angle measuring device, which relates to the technical field of aluminum profile processing, and comprises a table plate and a protractor, and the front side of the top of the table plate is provided with a convex plate; a cross rod is connected to the rear side of the convex plate in an attached mode, an inclined rod is arranged on the cross rod, and the bottom of the cross rod and the bottom of the inclined rod make contact with the table plate; a rotating shaft is arranged at the circle center of the protractor through a bearing, an indicating rod is arranged on the rotating shaft, an extension rod is arranged at the bottom of the indicating rod and connected with the inclined rod in an attached mode, the indicating rod is taken with one hand, the protractor is taken with the other hand, the extension rod at the bottom of the indicating rod is attached to the inclined rod, and then the protractor moves towards the protruding plate along the inclined rod. When the front side of the protractor is in parallel contact with the convex plate, the protractor is parallel to the cross rod, and the extension rod on the indicating rod is in parallel contact with the inclined rod, so that the scale indicated on the indicating rod is the inclination angle of the inclined rod.

The utility model relates to engineering quality detection field discloses a perpendicularity detection device for engineering quality detection, including sliding plate, the inner wall sliding connection of sliding plate has the fixed plate, the inner wall screw thread connection of sliding plate has the bolt, the inner wall of fixed plate is provided with plumb bob, the inner side wall fixed connection of sliding plate has the locating plate, the inner wall sliding connection of fixed plate has the limit stop, the inner wall of fixed plate inserts the protractor, the inner wall fixed connection of sliding plate has the baffle, the inner wall of fixed plate is provided with the activity mechanism, the inner wall of protractor is provided with the dismantlement subassembly, the activity mechanism includes the rack no.

The utility model provides a hydraulic engineering building inclination testing frame which comprises a vertical plate, a protractor is installed on the lower portion of one side face of the vertical plate, a measuring rod is rotatably installed on the side, away from the vertical plate, of the protractor, the measuring rod is arranged in the radial direction of the protractor, and a movable rod parallel to the measuring rod is arranged on one side of the measuring rod. Two guide rods are installed on the face, facing the measuring rod, of the movable rod, two guide holes matched with the measuring rod are formed in one face of the measuring rod, the two guide rods penetrate through the two guide holes respectively, a threaded hole is formed in one face of the measuring rod, the threaded hole is communicated with one guide hole, and the threaded hole is communicated with the other guide hole. A positioning screw used for limiting the relative position of the guide rod and the measuring rod is in threaded connection with the interior of the threaded hole, and a level gauge is connected to the upper portion of one side face of the vertical plate in an inserted mode.

The utility model relates to the technical field of furniture design, and discloses a portable foldable protractor for furniture design, which comprises a left block, the outer side of the left block is respectively provided with a right block and a storage mechanism, the storage mechanism comprises a transparent observation plate, the inner wall of the left block is fixedly connected with a fixed shell, the inner wall of the fixed shell is fixedly connected with a clockwork spring, and the clockwork spring is fixedly connected with the right block. A first rotating shaft is fixedly connected to the outer surface of the clockwork spring, an isolation block is fixedly connected to the inner wall of the left block, a winding block is fixedly connected to the left end of the first rotating shaft, a winding shell is arranged in the left block, and the left end of the first rotating shaft sequentially penetrates through the isolation block and the winding shell and extends into the winding shell. According to the portable foldable protractor for furniture design, digits on the surface of a cloth roll in the left block are observed through the transparent observation plate, the angle of a measured object is determined through the digits, and the problems that when a designer goes out for measurement, the protractor is inconvenient to carry and store, the operation difficulty of the designer is increased, and the working efficiency is affected are solved.

The utility model relates to a horizontal visual angle measuring device for a display, and the device comprises a workbench which is used for placing the display; the adjusting assembly comprises a connecting arm, an adjusting rod and a clamping piece, the adjusting rod and the clamping piece are vertically installed on the connecting arm, the connecting arm can drive the adjusting rod and the clamping piece to rotate in the horizontal direction under the action of external force, the brightness meter is driven to rotate, and the adjusting rod can move in the height direction relative to the connecting arm under the action of the external force; the measuring assembly comprises a mounting base mounted above the connecting arm, a protractor and an indicating piece, the protractor can rotate relative to the indicating piece along with the connecting arm so as to show the rotating angle of the connecting arm, and the measuring device is simple and compact in structure, small in occupied space and capable of being suitable for displays of different models and sizes; and the protractor can rotate relative to the indicating piece along with the connecting arm, so that a worker can conveniently indicate the scales on the protractor through the indicating piece to know the rotation angle of the brightness meter, and the measurement precision of the visual angle of the display in the horizontal direction is improved.