55results about How to "Easy to inspect visually" patented technology

The invention provides a PS-OCT-based three dimension visual nonnasality decayed tooth checking device and a checking method thereof. The method comprises: a polarized light beam is illuminated on an object to be checked by a self-focusing lens, a reflected light carrying the information of the object to be checked returns along the coming way, the reflected light carrying the information of the object to be checked and the reflected light from the exit end face of the self-focusing lens enter into the two arms of an interferometer and return to a coupler through a Faraday polariscope and perform interference; an optical fiber stretcher is adjusted to realize scanning in the longitudinal direction Z and synchronously the object to be checked is scanned in the horizontal direction X by a displacement platform to obtain the two-dimensional information of a certain cross section; the displacement platform is adjusted for carrying out scanning along the direction Y vertical to the cross section to obtain the plural two-dimensional images of different parts of the representative sample; the data is analyzed and processed with a software to obtain the structure and birefringence information of the object to be checked and reconstruct the three dimensional image thereof, and the result is displayed. The invention can realize high precise checking on the teeth without radiation, thus facilitating diagnosis on the decayed tooth.

The invention relates to a thickness controller of a cast-in-place concrete floor and a method of the thickness controller of the cast-in-place concrete floor. The controller comprises round steel, steel cushion slices and a sleeve pipe. Two ends of the round steel are threaded. Three steel cushion slices are arranged on the round steel, wherein one slice is a fixed steel cushion slice and the other two slices are movable steel cushion slices which are respectively arranged on upper and lower surfaces of a template. The sleeve pipe is arranged between the fixed steel cushion slice and the movable steel cushion slices and sleeved on the round steel. The method of the thickness controller of the cast-in-place concrete floor includes the following steps. A twist drill is used for drilling a hole in a plate bottom template before the concrete is cast. The sleeve pipe is cut and then sleeved on the round steel, and a steel cushion slice is sleeved on the round steel again. The round steel penetrates the hole in the plate bottom template. A steel cushion slice is additionally arranged below the plate bottom template and screwed tightly through a screw nut. In time of casing with concrete, an upper surface of the steel cushion slice welded above the round steel is used as panel elevation control. After the concrete is congealed, the round steel is removed. A sleeve pipe hole is used as a detection hole of thickness of a floor when an entity is detected. The thickness controller of the cast-in-place concrete floor and the method of the thickness controller of the cast-in-place concrete floor can control all sorts of plates with thickness ranging from 80mm to 320mm.

The invention discloses a measuring tool for detecting the spiral lift of a vibration absorber spring seat, comprising a base, wherein a stand seat and a plurality of measuring columns retractable up and down are arranged on the base. The measuring tool visually judges whether the spiral lift of the spring seat is eligible according to the retractable change amount of the measuring columns and by means of a tolerance range, and has the characteristics of use convenience and measurement accuracy; therefore, the problems of not easy positioning of the spring seat and inaccurate measurement are solved; moreover, the measuring tool is capable of causing the spring seat to detect a plurality of points in the working position, and simultaneously solves the problem that the spring seat is incapable of online verification and batch verification; therefore, the measuring tool has great popularization value in the detection process of similar products.

The invention discloses test paper for measuring moisture of transformer oil, preparation and an application. The test paper is prepared from a common cellulose paper piece with the cellulose content being 99.1%-99.6% as a carrier by soaking in a color developing agent, wherein the color developing agent is prepared from composition as follows: mixed powder of 38%-40% by mass of copper sulfate, 38%-40% by mass of calcium sulfide and 20%-22% by mass of acid blue which are weighed in an anhydrous environment is dissolved in petroleum ether, dispersed and mixed uniformly. The test paper is light blue and can detect trace moisture in the transformer oil sensitively, the color change process of the test paper is light blue, dark blue, aquamarine blue and black blue in sequence, the test paper is dark blue when the moisture content is 20 ppm, the color changes obviously, the period of validity is long, detection is convenient and visual, manufacture is simple, and the cost is low.

The invention relates to the field of ropes, in particular to an impact dynamic load test model device for a rope. The device comprises the rope, an impact mechanism, a tension sensor, a fixing mechanism and a release mechanism, wherein the tension sensor is arranged at the lower end of the fixing mechanism, the lower end of the tension sensor is connected to the rope, the lower end of the rope isconnected to the impact mechanism, the release mechanism can release the impact mechanism, the fixing mechanism and the release mechanism are both arranged on an elevated frame, and the release mechanism is fixed on the elevated frame through an initial fixing rope. The device has the advantages that the design is scientific and ingenious, workers can conveniently and intuitively detect the impact coefficient of the rope, a low-speed impact dynamic load simulation test can be carried out, so that the capacity of the structure for bearing low-speed and large-impact loads is verified, and the response characteristic of the structure under the low-speed impact load is obtained; and the standard for a novel impact experiment is provided, the test and operation of the workers in the field arefacilitated, and the device has the progressiveness and the instructive property in the field.

The invention provides a test connection device of a liquid crystal display screen, which is connected with a liquid crystal display screen to be tested and a test circuit so as to test the liquid crystal display screen to be tested. The test connection device is composed of at least one probe trace, wherein the probe trace respectively corresponds to at least one trace of the liquid crystal display screen to be tested; at least one probe trace is respectively and electrically connected with at least one trace of the liquid crystal display screen to be tested so as to transmit control signals transmitted by the test circuit to the liquid crystal display screen to be tested. The invention also provides a manufacture method for the test connection device of the liquid crystal display screen. The test connection device of the liquid crystal display screen and the manufacture method thereof have the advantages of simple operation, convenient identification, convenient use for manufacturers, little manufacture difficulty and lower cost, and overcome the defect that a metal probe lacerates an ITO trace during the test of short circuit. The invention not only can be used for shipment detection for the liquid crystal display screen, but also can be used for supplied materials detection for the liquid crystal display screen, besides, the liquid crystal display screen with the defects of short circuit and / or open circuit from flowing into the next procedure or client are prevented.

A fire extinguisher red light alarm includes a fire extinguisher cylinder body, a fixing leather ring, a spray nozzle, a handle, a safety pulling ring, and a pressure meter, which are connected to each other successively. A micro alarm is fixed to exterior of the pressure meter. A dial is installed in the pressure meter. A pointer is installed on the dial. A reed switch is installed at a position, which warns a value being lower than a minimum pressure, on the dial. A red light emitting diode is installed at the left lower part of the dial and a button battery is installed at the right lower part of the dial. The dial must be made from non-iron materials while the pointer must be made from a magnetic material. The fire extinguisher red light alarm can be used for conveniently and directly detecting pressure leakage, when the pressure of the fire extinguisher is lower than a warning value, the pointer of the pressure meter is moved into a red alarm zone. Because the pointer is magnetic, the reed switch is switched on, so that the red light emitting diode gives out light while the micro alarm gives out buzzer, which catches the attention and reminds people to deal with the fire extinguisher. The fire extinguisher red light alarm can achieve sound and light warning in a fire extinguisher of which the pressure is loss for reminding people to fill the fire extinguisher with agents, thereby ensuring safety.

The invention discloses a primer for detecting FHV-1, a nucleic acid capture gold-labeled test strip, a reagent kit and an application. A primer pair for detecting FHV-1 comprises a first primer and asecond primer with sequences shown as SEQ ID NO. 7 and SEQ ID NO. 8 respectively. The gold-labeled test strip comprises a lining plate, wherein a sample pad, a gold-labeled combining pad combined with an FITC gold-labeled antibody, a coating membrane and a water absorption pad are sequentially arranged on the upper end surface of the lining plate in a set direction; an invisible detection area combined with a digoxin antibody and an invisible control area combined with a sheep anti-rat secondary antibody are arranged on the coating membrane. The reagent kit comprises the primer pair and the nucleic acid capture gold-labeled test strip. A detection method of FHV-1 is high in specificity and sensitivity, accurate and quick, and has wide application prospects.

The invention aims to solve the problems that an existing bench drill is inconvenient to move and a drill bit cannot be detected in the working process, and discloses a movable bench drill with a detection function. The bench drill comprises a pulling rod, a motor, a connecting rod, a guide rod, a first guide frame, a first sleeve, a draught fan, a guide pipe, an air outlet head, a fastening screw, a first connecting plate, a second guide frame, a sliding plate, a liquid outlet, a spiral spring, a first contact plate, a base, a roller device, a warning lamp, a second connecting plate, a secondcontact plate, a mounting plate, a positioning ring, a clamping plate, a filter plate, a drill bit, a second sleeve, a feeding shaft, a main shaft frame, a connecting ring and a turntable. Accordingto the bench drill, through the first contact plate, the second contact plate, and the warning lamp, the strength of drilling on a workpiece can be detected in real time, and if the workpiece is drilled only when the strength is large, it proves that the drill bit is not sharp, and the resistance is large; and if the workpiece can be drilled when the strength is not large, it proves that the drillbit is sharp, so that the sharpness degree of the drill bit can be rapidly detected.

The invention relates to a direct-current transmission converter valve lightning arrester monitoring device and method. The direct-current transmission converter valve lightning arrester monitoring device comprises a monitoring loop installed between the end of a lightning arrester and a shielding ring, the monitoring loop is used for detecting the current of the lightning arrester, at least one pair of plate electrodes with air gaps are arranged in the monitoring loop in a series mode, and the action condition of the lightning arrester is monitored by detecting whether the plate electrodes break down or not. The direct-current transmission converter valve lightning arrester monitoring method comprises the step that whether the lightning arrester acts or not is detected by detecting the breakdown phenomenon of the plate electrodes. Due to the fact that the lightning arrester of a converter valve is installed in a valve hall of the converter valve, the voltage on the lightning arrester is quite high, the electromagnetic environment of the lightning arrester is quite complex, and electromagnetic interference is serious. The monitoring loop is not provided with any electronic part and installed between the end of the lightning arrester and the shielding ring, and thus the interference-resisting capability of the monitoring device is greatly improved.

The invention discloses a remote monitoring and expert diagnosis system for a diesel generating set. The system comprises a data collection end which is used for collecting the state data of the working process of the diesel generating set, a data management unit which is used for achieving the transmission, storage and processing of data, a monitoring end which is used for checking the working state of the diesel generating set, and an analysis and diagnosis report unit which is used for analyzing the power supply quality of the diesel generating set. The system can be used for remote monitoring and data storage recording of the diesel generating set, and meanwhile, the diesel generating set fault diagnosis expert system provides opinions for fault judgment, realizes operation maintenanceof the diesel generating set, improves the operation safety level of the diesel generating set, reduces the operation and maintenance cost to the maximum extent, and the unattended operation and intelligent operation and maintenance level of the diesel generating set is effectively improved.

The invention discloses a tester for anti-collapse performance of a loose formation drilling mud protection wall and a using method thereof, and belongs to the field of underground geotechnical engineering construction. According to the tester, an outer cylinder and a porous inner layer annular tube are used for constructing a loose sand annular accumulation body, the practical situation of drilling hole walls of loose formation such as various sand and gravel can be simulated, and the detachable porous inner layer annular tube is used for realizing the injection of mud or clear water in the loose sand annular accumulation body, after the porous inner layer annular tube is disassembled, the state of the loose sand annular accumulation body in clear water soaking is observed to intuitivelytest the anti-collapse effect of the mud protection wall, and reliable basis is provided for smooth construction of various drilling engineering of the complex formation; and moreover, the tester hasthe advantages of being simple in manufacturing, convenient in operation, capable of meeting environmental protection requirements, low in economic cost, capable of being repeatedly used, high in intuition and the like, has great popularization and application value, and has great significance in ensuring the mud use safety of the drilling engineering of the loose formation such as the sand and the gravel.

The invention discloses an ultrasonic flowmeter, and particularly relates to the field of ultrasonic passenger flow volume collection devices. The defects that according to existing passenger flow volume measurement, a measuring element needs to be installed at a passenger passing position, and dynamic state of passenger flow is likely to be changed are overcome. The ultrasonic flowmeter comprises an ultrasonic transmitting transducer and a receiver. The ultrasonic transmitting transducer and the receiver are each provided with a piezoelectric element. The ultrasonic transmitting transducer is connected with an ultrasonic transmitting unit. The receiver is connected with a signal processing unit. The signal processing unit comprises a calculation instrument and a signal amplifier. The ultrasonic transmitting unit and the signal processing unit are connected with a microprocessor control unit. A display device is connected to the microprocessor control unit. The ultrasonic transmitting transducer is made of piezoelectric materials. The display device comprises a computer.

The invention discloses a rapid assembling method of a numerically-controlled part adding tool. According to the method, auxiliary measurement points of a part are additionally arranged on the tool, precise positioning of the part is achieved through a laser tracker, on-site dynamic measurement is achieved for detection of the assembled part, the difficult situation that normal machining and measuring are separated is avoided, therefore, numerically-controlled part adding tool manufacturing is rapider and simpler, the manufacturing assembly precision is high, and detection is more visual.

The invention relates to an integrated digital weather sensor. The integrated digital weather sensor is composed of a temperature compensating device, a wind pressure measuring device and a digital power supply device. The temperature compensating device is connected with the wind pressure measuring device through a common part upper disk (11), and a part outer barrel (9) in the wind pressure measuring device is integrated with a part connecting component (31) in the digital power supply device through mutually fit threads. The integrated digital weather sensor can realize the integration of the measuring device and the power supply device, and is more convenient for carrying and mounting; the temperature compensating device is independent from a wind speed measuring device, and a measurement result is more accurate; the measurement result is output as a digital signal, and the anti-jamming capability is stronger and the performance is more stable; and the integrated digital weather sensor can provide environment parameters such as wind speed, wind pressure, air temperature and the like for a vehicle-mounted fire control system.

The invention relates to a fluorescent probe for detecting a sulfur dioxide derivative, a detection object, and a preparation method and application of the fluorescent probe. The sulfur dioxide derivative is a salt with sulfite or bisulfite ions, and the structural formula of the fluorescent probe is as described in the specification. In the formula, TfO<-> is trifluoromethanesulfonate ions. The fluorescent probe disclosed by the invention is a colorimetric far-infrared sulfite / bisulfite fluorescent probe, has full water solubility, can be directly dissolved in water, and does not need to be dissolved by an additional organic solvent; the response of the probe is fast, and detection can be completed within 15 s; a color development mode during detectionis a mode from a colorless state to acoloredstate, so direct naked eye detection can be realized, the detection is more visual and convenient, and the rate of false positive is low; and the lowest detection limit of sodium hydrogen sulfite is 0.11 [mu]M, and sensitivity is higher. The probe of the invention not only can meet the detection requirements of sulfite / bisulfite in organisms, but also can realize rapid detection of sulfite / bisulfite in food or medicines.

The invention aims to solve the detection problem of river channel slope protection, and discloses a river channel slope protection detection device for a water conservancy project. The river channel slope protection detection device comprises a motor, wherein the upper side surface of the motor is fixedly connected with an elastic rope; the outer end of the elastic rope is fixedly connected with a cover plate; a cleaning layer is fixedly arranged on the inner side surface of the cover plate; a drill rod is arranged on the right side of the motor; a handle is fixedly arranged on the left side of the surface of the motor; a waterproof cover is arranged on the motor; a connecting rod is fixedly arranged on the lower side of the motor; the lower end of the connecting rod is fixedly connected with a sliding frame; a sliding pipe is arranged on the side wall of the sliding frame in a sleeving mode; a spiral spring is fixedly connected between the sliding pipe and the right end of the sliding frame; the lower side surface of the sliding pipe is fixedly connected with a fixing rod; a material passing cylinder is fixedly arranged at the lower end of the fixing rod; and a discharging pipe is fixedly arranged at the right end of the material passing cylinder. According to the river channel slope protection detection device, the drill rod can be conveniently used for drilling a hole in the slope protection for visual detection, the fullness degree in the slope protection can be known, meanwhile, the slope protection can be conveniently subjected to full protection, and the slope protection can be prevented from collapsing.

The invention discloses a tunnel construction monitoring measurement and back break measurement control technology. The control technology comprises the following steps of (1), performing tunnel excavation construction, scanning a tunnel excavation section, obtaining three-dimensional point cloud data, and performing data processing; (2), obtaining an actual three-dimensional model of the excavated tunnel, and synthesizing a theoretically designed tunnel model and the actual three-dimensional model to represent back break measurement information of the tunnel; (3), effectively controlling over-break and under-break conditions of the tunnel; (4), formulating a tunnel construction monitoring and measuring scheme, and carrying out primary support on the tunnel; (5), processing and analyzing data, and determining the construction time of an inverted arch and a secondary lining of the excavated tunnel, and determining the deformation grade condition of the tunnel; and (6), establishing a construction control standard of the excavated tunnel, and guaranteeing that tunnel construction is completed. The control technology can meet the precision requirement of back break measurement, is higher in efficiency than a traditional detection mode, and can be applied to safety monitoring of various tunnel projects.

A front axle steering system fatigue test device disclosed by the present invention comprises a test bench, the edge of the test bench is fixedly connected with an edge frame, the two sides of the edge frame are fixedly provided with wheel disc limiting members, and one side of the top of the edge frame is rotatably connected with a test driving member; a pull rod moving groove is formed in one side of the top of the test bed, rocker arm moving grooves are formed in the two ends of the pull rod moving groove, and a pull rod test piece is fixedly installed on the other side of the top of the edge frame. During use, power input is performed on the whole front axle steering system, the wheel disc limiting pieces are used for pushing and limiting the two steering wheel discs, and the stability of the whole position posture of the front axle steering system in the testing process is improved; by arranging the pull rod test piece, the pull rod replacement plate and other structures, independent detection of the transmission pull rod and the trapezoidal rocker arm is achieved, and detection is more visual and convenient.

The invention discloses an amplification primer composition and a kit for detecting a new coronavirus. The amplification primer composition comprises a first primer group and a second primer group, the first primer group comprises a first forward primer and a first reverse primer, the second primer group comprises a second forward primer and a second reverse primer. In addition, .four basic groups in each sequence of the first forward primer, the first reverse primer, the second forward primer and the second reverse primer are modified by locked nucleic acid, one of the four basic groups is a 3'terminal basic group, and the distance between every two adjacent basic groups modified by the locked nucleic acid is 3-6 basic groups; the basic group modified by the locked nucleic acid is adenine and / or thymine. The invention also discloses the kit for detecting the new coronavirus. According to the amplification primer composition and the kit for detecting the new coronavirus, the kit has the characteristics of high sensitivity, strong specificity, good stability and the like, can be used for rapid detection of new coronavirus pneumonia, and has a wide application prospect.

The invention discloses a gas leakage prompting device for a gas booster station so that a problem that the existing device can not detect the gas leakage of the pipeline quickly and conveniently canbe solved. The prompting device is composed of a motor, a rotating shaft, a push block, a turntable, a push plate, a first spiral spring, a push rod, a scraper blade, guide wheels, wheel frames, mounting rods, sliding blocks, connecting rods, stopper blocks, an adsorption layer, a liquid storage tank, a guide frame, a mounting plate, a positioning rod, a sun shield, a magnifying glass, a connecting block, a fixation plate, a holding rod, a mounting block, a support rod, a holding ring, a second spiral spring and a guide rod. With the motor, the liquid storage tank can be pushed repeatedly andconveniently and thus the adsorption layer is able to coat suds on the surface of the pipeline, so that the user is able to detect the gas leakage of the pipeline visually and conveniently. Therefore,the airtightness of the pipeline is detected quickly. The gas leakage prompting device is worth popularizing.

The invention discloses a sulphur master batch detection method. According to the method, an open mill is used to roller and slide a raw material of master batch to detect the disperse uniform degreeof sulphur master batch particles. The method at least comprises the following steps that 1) soft semi-finished master batch products kneaded by a kneader are selected; 2) the semi-finished master batch products in the step 1) are input to the open mill for tabletting; 3) the semi-finished products in the step 2) are cut into slices; 4) the slices of the step 3) are used as samples to compare colors of the samples, a Pantone color card 3945C is used as standard colors, and the sample whose color ranges from 393C to 3965C is determined to be qualified. The method can be used to detect the dispersibility of the sulphur master batch in the production process, and quality control of the products can be enhanced.

The invention relates to an acousto-optic wireless high-voltage detection device, which is specifically applied in the field of outdoor AC high-voltage line maintenance; it includes a housing installed on a utility pole through a connecting buckle, a circuit device installed in the housing, a vertical heat dissipation plate, The solar panel installed above the shell through the connecting pipe and the insulating and moisture-proof sealed box installed on one side of the shell and equipped with desiccant; the circuit device includes a wireless control circuit, an auxiliary circuit and a detection circuit; the present invention forms a vertical The heat dissipation channel acts as a chimney effect, which is conducive to heat dissipation; energy saving and environmental protection; keeps all parts dry and insulated; improves work efficiency and improves work comfort; safe and reliable, easy maintenance; convenient and intuitive detection; simplified circuit structure, intelligent control; reduce electromagnetic pollution .

The invention relates to the technical field of pipeline valve detection, in particular to pipeline valve detection equipment and a detection method thereof. The pipeline valve detection equipment comprises a pipe body, a valve plate, a hand wheel, a ventilation mechanism and an early warning mechanism, wherein the valve plate is arranged in the pipe body, the hand wheel is fixedly connected to the upper portion of the valve plate, and an air bag and a hose are arranged on the side face of the valve plate; a lap-joint block is arranged above the pipe body, a lower-layer cavity of the lap-joint block communicates with the hose, the ventilation mechanism is arranged in the lap-joint block, a lap-joint cylinder is fixedly connected to the top end of the lap-joint block, and the early warning mechanism is arranged on the right side of the lap-joint cylinder. The pipeline valve detection equipment and the detection method thereof have the advantages that improvement is made on the basis of the prior art, the valve plate is difficult to rotate under overhigh pressure by utilizing the early warning mechanism and a pretreatment mechanism on the equipment, and the safety during testing is ensured.

The invention discloses a high-precision testing system for a solid-state hard disk, which includes an operating table, a test box is fixedly installed on the top of the operating table, a temperature testing mechanism is fixedly installed on the top of the test box, and a test box is fixedly installed on the left side of the test box. Humidity testing mechanism, the bottom of the test box is fixed with an anti-seismic testing mechanism, the top of the seismic testing mechanism is fixed with a positioning tool, and the interior of the positioning tool is clamped with a solid-state hard disk body, and the inside of the test box is right The upper end of the side is fixed with a conductive mechanism, and the lower end of the conductive mechanism is electrically connected to the solid-state hard disk body; this equipment can test the solid-state hard disk more comprehensively and accurately by setting up a temperature testing mechanism, an anti-seismic testing mechanism and a humidity testing mechanism. At the same time, the installation mechanism is provided, which makes the installation and disassembly of the device more convenient, and further makes the device more practical, has a wider application prospect, and is worthy of popularization and use.

The invention relates to a sound-type wireless high voltage detection apparatus which is specifically used in the outdoor alternating current high voltage line maintenance field. The apparatus comprises a shell installed on a telegraph pole through a connection buckle, a circuit device, vertical cooling plates, a solar cell panel and an insulated moisture-proof sealing box. A vertical cooling channel is formed between the adjacent vertical cooling plates. The circuit device comprises a wireless control circuit, an auxiliary circuit and a detection circuit. In the apparatus of the invention, through the vertical cooling plates, the vertical cooling channel is formed, and a chimney effect is achieved, which is good for cooling, energy saving and environmental protection and maintenance of drying insulation of each component; through wireless remote control, work efficiency and a work comfort level are increased; safety and reliability are achieved and maintenance is convenient; the detection is convenient and intuitive; through a decoding decoder module, a circuit structure is simplified and intelligent control is realized; a nylon lining layer is used to carry out insulation and a metal outer wall is used to reduce electromagnetic pollution; and a wireless signal is used to realize long distance remote control.

The invention discloses a steel structure anti-pressure capability detection device which comprises vertical plates, adjusting mechanisms and locking mechanisms are installed in the middles of the vertical plates, a detection mechanism is installed between the vertical plates at the top ends of the adjusting mechanisms and the locking mechanisms, supporting mechanisms are installed between the vertical plates at the bottom ends of the adjusting mechanisms and the locking mechanisms, clamping plates are fixedly welded to the middles of the vertical plates, clamping holes are formed in the middles of the clamping plates, the adjusting mechanisms are installed on the two sides of the clamping holes, the locking mechanisms are installed at the top ends of the adjusting mechanisms, a top plate is welded to the two sides of the top ends of the vertical plates, the detection mechanism is fixedly installed at the top end of the top plate, a bottom plate is welded to the bottom ends of the vertical plates, and the supporting mechanisms are fixedly installed on the bottom plate. The device has the advantages of improving the accuracy of the compressive resistance of the steel structure, improving the detection efficiency, reducing the physical labor of the human body, is simple to use and convenient to operate, and firmly fixes the steel structure.

The invention discloses test paper for measuring moisture of transformer oil, preparation and an application. The test paper is prepared from a common cellulose paper piece with the cellulose content being 99.1%-99.6% as a carrier by soaking in a color developing agent, wherein the color developing agent is prepared from composition as follows: mixed powder of 38%-40% by mass of copper sulfate, 38%-40% by mass of calcium sulfide and 20%-22% by mass of acid blue which are weighed in an anhydrous environment is dissolved in petroleum ether, dispersed and mixed uniformly. The test paper is light blue and can detect trace moisture in the transformer oil sensitively, the color change process of the test paper is light blue, dark blue, aquamarine blue and black blue in sequence, the test paper is dark blue when the moisture content is 20 ppm, the color changes obviously, the period of validity is long, detection is convenient and visual, manufacture is simple, and the cost is low.