CN108321766A - Charge touching device and system - Google Patents

Charge touching device and system Download PDF

Info

Publication number
CN108321766A
CN108321766A CN201810391912.4A CN201810391912A CN108321766A CN 108321766 A CN108321766 A CN 108321766A CN 201810391912 A CN201810391912 A CN 201810391912A CN 108321766 A CN108321766 A CN 108321766A
Authority
CN
China
Prior art keywords
electrification
console
firewire
zero curve
touching device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201810391912.4A
Other languages
Chinese (zh)
Inventor
李晓莉
许晓春
陈方
刘艳君
陈伟军
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangdong Power Grid Co Ltd
Huizhou Power Supply Bureau of Guangdong Power Grid Co Ltd
Original Assignee
Guangdong Power Grid Co Ltd
Huizhou Power Supply Bureau of Guangdong Power Grid Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangdong Power Grid Co Ltd, Huizhou Power Supply Bureau of Guangdong Power Grid Co Ltd filed Critical Guangdong Power Grid Co Ltd
Priority to CN201810391912.4A priority Critical patent/CN108321766A/en
Publication of CN108321766A publication Critical patent/CN108321766A/en
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Elimination Of Static Electricity (AREA)

Abstract

The present invention provides electrification touching devices and system, are related to power equipment applied technical field, wherein the electrification touching device includes:Security isolation fence, console, felt pad, conductor rods and experience contact, felt pad is arranged in the lower section of security isolation fence, contact is experienced to be arranged on conductor rods, experience contact is connected with console, during use, security isolation fence is for firewire and zero curve to be isolated, whether the weight that console is used to detect on felt pad changes, and, detect weight increase when detected target (such as, people) have arrived at rear generation target arriving signal on felt pad, console can receive target arriving signal in this way, detect the connection of connection and firewire or zero curve when experience contact is triggered, in this way, electric energy in firewire or zero curve is conveyed to target internal, to the safe and reliable process for realizing electrification and touching.

Description

Charge touching device and system
Technical field
The present invention relates to power equipment applied technical fields, more particularly to electrification touching device and system.
Background technology
In supply of electric power, the alternating voltage for accessing line is usually 220 volts (referred to as lying prostrate, symbol is V), above-mentioned The connecting line of alternating voltage has two, wherein single line access the earth, is called " zero curve " (N), another single line is called firewire 〔L〕.That difference lies in the electric currents under normal circumstances, flowing through zero curve is identical as firewire (for single-phase electricity) for zero curve and ground wire.But work as During use, zero curve is longer, and it is thinner when, that is, when line resistance is larger, if the electric current by zero curve is larger, circuit On have pressure drop, the current potential of zero curve is no longer zero volt.But when the design of general circuit, it can consider to limit this voltage, it is made to connect Nearly 0 volt.
Since the voltage of alternating current is higher, dangerous also larger, and therefore, the reason of understanding human electric shock, electric shock mode etc. are known Know and have very great help to preventing from getting an electric shock, but how to allow people to undergo and touch electric conductor, it will further deepens to endanger getting an electric shock Understanding, the method actively to grasp correct pre- protection against electric shock so that experiencer actively takes security protection in work, life Measure prevents the generation of electric shock accidents.And if directly electrification touch relate to personal safety, in view of danger coefficient compared with Height, there presently does not exist fairly perfect electrifications to touch experiential method.
Invention content
In view of this, the embodiment of the present invention has been designed to provide electrification touching device and system, by the way that safety is arranged Segregator barriers, console, felt pad, conductor rods and experience contact etc., touch for experience electrification and provide safe and reliable method.
In a first aspect, an embodiment of the present invention provides electrification touching devices, including:Security isolation fence, console, insulation Pad, conductor rods and experience contact;
The felt pad is arranged in the lower section of the security isolation fence, and the experience contact is arranged in the conductor rods On, the experience contact is connected with the console;
The security isolation fence, for firewire and zero curve to be isolated;
Whether the console, the weight for detecting on the felt pad change, and, detecting weight increase Shi Shengcheng target arriving signals;
The console is additionally operable to receiving the target arriving signal, and, detect that the experience contact is triggered The connection of Shi Liantong and firewire or zero curve.
With reference to first aspect, an embodiment of the present invention provides the first possible embodiments of first aspect, wherein band Electric touching device further includes display lamp, and the display lamp is connected with the console, and the display lamp is connected in parallel on firewire or zero On line;
The display lamp, for being connected in the experience contact and being lighted after firewire or zero curve.
With reference to first aspect, an embodiment of the present invention provides second of possible embodiments of first aspect, wherein institute Console is stated, is additionally operable to detect whether the weight on the felt pad changes, and, mesh is generated when detecting weight saving Mark disappearance of signal;
The display lamp, for extinguishing after receiving the target disappearance of signal.
With reference to first aspect, an embodiment of the present invention provides the third possible embodiments of first aspect, wherein band Electric touching device further includes leakage switch, and the leakage switch is connected with the console, and, the leakage switch is arranged in fire On line or zero curve;
The leakage switch, for generating electric leakage alarm when detecting that firewire or zero curve leak electricity;
The console, for cutting off experience contact and the firewire or zero curve after receiving the electric leakage alarm Connection.
The third possible embodiment with reference to first aspect, an embodiment of the present invention provides the 4th kind of first aspect Possible embodiment, wherein electrification touching device further includes choked flow fuse, the choked flow fuse and the leakage switch Series winding;
The choked flow fuse fuses when exceeding threshold value for the electric current in firewire or zero curve.
With reference to first aspect, an embodiment of the present invention provides the 5th kind of possible embodiments of first aspect, wherein also Including insulating support rod, the material of the insulating support rod is epoxy resin, and, the height of the insulating support rod is adjustable, institute Insulating support rod is stated to be arranged in the lower section of the conductor rods.
The third possible embodiment with reference to first aspect, an embodiment of the present invention provides the 6th kind of first aspect Possible embodiment, wherein electrification touching device further includes detector, and the detector is connected with the leakage switch;
Whether the detector, the folding for detecting the leakage switch are normal.
Second aspect, an embodiment of the present invention provides electrification touch systems, including:
Fixed fence and electrification touching device described in any one of the above embodiments;
The fixed fence is centered around the surrounding of the electrification touching device;
The fixed fence causes to constitute circuit generation electric shock accidents for avoiding target from being in contact with the external world.
Electrification touching device provided in an embodiment of the present invention and system, wherein the electrification touching device includes:Security isolation Fence, console, felt pad, conductor rods and experience contact, the connection relation between above-mentioned all parts are:Felt pad setting exists The lower section of security isolation fence, experience contact is arranged on conductor rods, in general, conductor rods have two, respectively with zero curve or fire Line be connected, experience contact be connected with console, in use, security isolation fence be used for by firewire and zero curve progress every From people can only touch firewire or zero curve that is, after isolation, it is difficult to form closed circuit, also, console is used Whether change in the weight on detection felt pad, also, target arriving signal is generated when detecting weight increase, that is, examines It measures and generates target arriving signal when the targets such as someone enter detection zone, later, console is additionally operable to arrive receiving target Up to signal, also, the connection of connection and firewire or zero curve when experience contact is triggered is detected, since Target Station is good Single-point contact firewire or zero curve on felt pad, to which the potential difference on effective guarantee human body is less than the safe voltage of human body So that the current potential of human body is formed equipotential with conductor to make the electric current in firewire or zero curve flow into objective body, passes through In the electrification touching device that the above method is formed, firewire and zero curve were isolated before this, are setting by felt pad later It sets and further enhances safety precaution, and electric current is flowed into the inside of target when target presses experience contact, to which safety has The electrification for realizing target of effect touches experience.
Other features and advantages of the present invention will illustrate in the following description, also, partly become from specification It obtains it is clear that understand through the implementation of the invention.The purpose of the present invention and other advantages are in specification, claims And specifically noted structure is realized and is obtained in attached drawing.
To enable the above objects, features and advantages of the present invention to be clearer and more comprehensible, preferred embodiment cited below particularly, and coordinate Appended attached drawing, is described in detail below.
Description of the drawings
It, below will be to specific in order to illustrate more clearly of the specific embodiment of the invention or technical solution in the prior art Embodiment or attached drawing needed to be used in the description of the prior art are briefly described, it should be apparent that, in being described below Attached drawing is some embodiments of the present invention, for those of ordinary skill in the art, before not making the creative labor It puts, other drawings may also be obtained based on these drawings.
Fig. 1 shows the connection figure for the electrification touching device that the embodiment of the present invention is provided;
Fig. 2 shows the connection diagrams for the electrification touching device that the embodiment of the present invention is provided;
Fig. 3 shows the structural framing figure for the electrification touch system that the embodiment of the present invention is provided;
Fig. 4 shows the structure connection figure for the electrification touch system that the embodiment of the present invention is provided.
Icon:1- felt pads;2- consoles;3- experiences contact;4- display lamps;5- security isolation fence;6- fixed fences; 7- conductor rods.
Specific implementation mode
Below in conjunction with attached drawing in the embodiment of the present invention, technical solution in the embodiment of the present invention carries out clear, complete Ground describes, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Usually exist The component of the embodiment of the present invention described and illustrated in attached drawing can be arranged and be designed with a variety of different configurations herein.Cause This, the detailed description of the embodiment of the present invention to providing in the accompanying drawings is not intended to limit claimed invention below Range, but it is merely representative of the selected embodiment of the present invention.Based on the embodiment of the present invention, those skilled in the art are not doing The every other embodiment obtained under the premise of going out creative work, shall fall within the protection scope of the present invention.
The voltage of alternating current is higher, dangerous also larger, therefore, it is impossible to after directly understanding human contact's alternating current by touching Reaction, but how to allow people undergo touch electric conductor, it will further deepen to get an electric shock harm understanding, actively to slap The method for holding correct pre- protection against electric shock so that experiencer actively takes safety prevention measure in work, life, prevents electric shock accidents Generation.Higher in view of danger coefficient, there presently does not exist improve effective electrification to touch experience equipment.
Based on this, an embodiment of the present invention provides electrification touching device and systems, are described below by embodiment.
Embodiment 1
Referring to Fig. 1 and Fig. 2, the electrification touching device that the present embodiment proposes specifically includes:Security isolation fence 5, console 2, felt pad 1, conductor rods 7 and experience contact 3, felt pad are arranged in the lower section of security isolation fence, setting felt pad be in order to Target (for example, people) is allowed to be electrically insulated between the earth, experience contact is arranged on conductor rods, the body on said one conductor rods Testing contact can be arranged multiple, and to facilitate more people to be carried out at the same time experience, also, it is electric conductor to experience contact, for example, copper wire etc., Experience contact is connected with console, i.e., experience contact is triggered, and (i.e. target touches experience contact, alternatively, target connection setting exists Wiring etc. on experience contact) after can be connected to console.When in use, security isolation fence be used for by firewire and zero curve into Whether row isolation, the weight that console is used to detect on felt pad change, also, generate mesh when detecting weight increase Arriving signal is marked, console is additionally operable to receiving target arriving signal, also, detects console when experience contact is triggered The connection of connection and firewire either zero curve is pressing the mesh of experience contact to introduce the electric current in firewire or zero curve Mark.
In addition, electrification touching device further includes insulating support rod, the material of insulating support rod is epoxy resin, epoxy resin It refer to the general name of a kind of polymer containing more than two epoxy groups in molecule.It is epoxychloropropane and bisphenol-A or polynary The height of the polycondensation product of alcohol, high temperature resistant, stable chemical performance, good insulation preformance, also, insulating support rod is adjustable, and experience is touched Point is arranged on conductor rods, and insulating support rod is arranged in the lower section of conductor rods, by adjusting the height of insulating support rod, such energy Enough ensure that the people of different heights can touch the experience contact on the conductor rods.
In addition, electrification touching device further includes display lamp 4, display lamp is connected with console, and when in use, display lamp is in parallel Display lamp is used to be connected in experience contact and light after firewire or zero curve on firewire either zero curve, passes through the point of display lamp It is bright that target current can be prompted to have already accessed in experience contact, and can outwardly send out effective prompt.If display lamp point Bright exception then needs to check whether the connection of the components such as above-mentioned console, display lamp is correct, and whether all parts itself damage Deng.
Also, whether the weight that console is additionally operable on detection felt pad changes, and is given birth to when detecting weight saving At target disappearance of signal, that is, determines and generate target disappearance of signal when target (for example, people) etc. has been moved off felt pad, in this feelings Under condition, display lamp extinguishes after receiving target disappearance of signal, disappears so as to effectively save the electric energy in firewire or zero curve Consumption.
In addition, electrification touching device further includes leakage switch, leakage switch is connected with console, also, leakage switch is set It sets on firewire or zero curve, when in use, leakage switch is used to generate electric leakage police when detecting that firewire or zero curve leak electricity Report, and the connection of console cut-out experience contact and firewire or zero curve after receiving electric leakage alarm can be made, to effectively Prevent firewire or zero curve the electric leakage security risk caused by target.
In addition, electrification touching device further includes choked flow fuse, choked flow fuse is contacted with leakage switch, when in use, Choked flow fuse fuses when exceeding threshold value for the electric current in firewire or zero curve, so as to make leakage switch disconnect, by In the centre position in firewire or zero curve is arranged in leakage switch, and after leakage switch disconnection, firewire or zero curve i.e. can not be just Often transmission electric current, so as to avoid the excessive possibility for causing security threat to target of electric current.
In addition, in order to further ensure that the touch safety of target, electrification touching device further include detector, detector and leakage Electric switch is connected, and whether the folding that detector is used to detect leakage switch is normal, in general, detection process can be according to preset Whether time interval carries out, normally hidden to exclude safety caused by leakage switch failure by the performance for detecting leakage switch Suffer from.
In conclusion electrification touching device provided in this embodiment includes:Security isolation fence, felt pad, is led at console Body rod and experience contact, felt pad are arranged in the lower section of security isolation fence, and experience contact is arranged on conductor rods, experiences contact It is connected with console, during use, security isolation fence is for firewire and zero curve to be isolated, and console is for detecting absolutely Whether the weight on edge pad changes, also, generates target arriving signal when detecting weight increase, and console is additionally operable to Target arriving signal is being received, also, is detecting the connection of connection and firewire or zero curve when experience contact is triggered, to So that the electric current in firewire or zero curve is flowed into objective body, is handled by using above-mentioned electrification touching device, it before this will be fiery Line and zero curve are isolated, and are that the safety for touching electric conductor is further enhanced by the setting of felt pad later, and in mesh For mark by the inside that electric current is flowed into target when experience contact, the electrification for realizing target touches experience, safe and convenient.
Embodiment 2
Referring to Fig. 3 and Fig. 4, present embodiments providing electrification touch system includes:The band of fixed fence 6 and any of the above-described Electric touching device, fixed fence are centered around the surrounding of electrification touching device, and fixed fence will be for that will charge touching device and the external world It is isolated.Need exist for illustrating, fixed fence generally around electrification touching device surrounding, also, in order to Inside to charging touching device is effectively isolated, and target and the external world can also be effectively separated by fixed fence, be avoided Target is in contact with the external world, causes to constitute circuit electric shock accidents occurs, that is, avoid people and meanwhile contact firewire and zero curve can Energy property, to further enhance Electrical Safety.
In conclusion electrification touch system provided in this embodiment includes:The electrification of fixed fence and any of the above-described is touched Device is touched, fixed fence is centered around the surrounding of electrification touching device, and when in use, fixed fence can carry out target with extraneous Isolation, avoids target from being in contact with the external world, causes to constitute circuit generation electric shock accidents, to further ensure that electrification touches Device it is safe to use.
It is apparent to those skilled in the art that for convenience and simplicity of description, the system of foregoing description Specific work process, can refer to previous embodiment in corresponding process, details are not described herein.
In addition, in the description of the embodiment of the present invention unless specifically defined or limited otherwise, term " installation ", " phase Even ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or be integrally connected;It can Can also be electrical connection to be mechanical connection;It can be directly connected, can also indirectly connected through an intermediary, Ke Yishi Connection inside two elements.To those skilled in the art, it can understand above-mentioned term in the present invention with concrete condition Concrete meaning.
In the description of the present invention, it should be noted that term "center", "upper", "lower", "left", "right", "vertical", The orientation or positional relationship of the instructions such as "horizontal", "inner", "outside" be based on the orientation or positional relationship shown in the drawings, merely to Convenient for the description present invention and simplify description, do not indicate or imply the indicated device or element must have a particular orientation, With specific azimuth configuration and operation, therefore it is not considered as limiting the invention.
Finally it should be noted that:Embodiment described above, only specific implementation mode of the invention, to illustrate the present invention Technical solution, rather than its limitations, scope of protection of the present invention is not limited thereto, although with reference to the foregoing embodiments to this hair It is bright to be described in detail, it will be understood by those of ordinary skill in the art that:Any one skilled in the art In the technical scope disclosed by the present invention, it can still modify to the technical solution recorded in previous embodiment or can be light It is readily conceivable that variation or equivalent replacement of some of the technical features;And these modifications, variation or replacement, do not make The essence of corresponding technical solution is detached from the spirit and scope of technical solution of the embodiment of the present invention, should all cover the protection in the present invention Within the scope of.Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (8)

1. charging touching device, which is characterized in that including:Security isolation fence, console, felt pad, conductor rods and experience are touched Point;
The felt pad is arranged in the lower section of the security isolation fence, and the experience contact is arranged on the conductor rods, institute Experience contact is stated to be connected with the console;
The security isolation fence, for firewire and zero curve to be isolated;
Whether the console, the weight for detecting on the felt pad change, and, it is given birth to when detecting weight increase At target arriving signal;
The console is additionally operable to receiving the target arriving signal, and, it detects and connects when the experience contact is triggered The logical connection with firewire or zero curve.
2. electrification touching device according to claim 1, which is characterized in that further include display lamp, the display lamp and institute It states console to be connected, the display lamp is connected in parallel on firewire or zero curve;
The display lamp, for being connected in the experience contact and being lighted after firewire or zero curve.
3. electrification touching device according to claim 1, which is characterized in that the console is additionally operable to detect described exhausted Whether the weight on edge pad changes, and, target disappearance of signal is generated when detecting weight saving;
The display lamp, for extinguishing after receiving the target disappearance of signal.
4. electrification touching device according to claim 1, which is characterized in that further include leakage switch, the leakage switch It is connected with the console, and, the leakage switch is arranged on firewire or zero curve;
The leakage switch, for generating electric leakage alarm when detecting that firewire or zero curve leak electricity;
The console, the company for cutting off the experience contact and firewire or zero curve after receiving the electric leakage alarm It connects.
5. electrification touching device according to claim 4, which is characterized in that further include choked flow fuse, the choked flow is protected Dangerous silk is contacted with the leakage switch;
The choked flow fuse fuses when exceeding threshold value for the electric current in firewire or zero curve.
6. electrification touching device according to claim 1, which is characterized in that further include insulating support rod, the insulation branch The material of strut is epoxy resin, and, the height of the insulating support rod is adjustable, and the insulating support rod is arranged in the conductor The lower section of bar.
7. electrification touching device according to claim 4, which is characterized in that further include detector, the detector and institute Leakage switch is stated to be connected;
Whether the detector, the folding for detecting the leakage switch are normal.
8. charging touch system, which is characterized in that including:Fixed fence and such as claim 1-7 any one of them electrification are touched Touch device;
The fixed fence is centered around the surrounding of the electrification touching device;
The fixed fence causes to constitute circuit generation electric shock accidents for avoiding target from being in contact with the external world.
CN201810391912.4A 2018-04-26 2018-04-26 Charge touching device and system Pending CN108321766A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810391912.4A CN108321766A (en) 2018-04-26 2018-04-26 Charge touching device and system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810391912.4A CN108321766A (en) 2018-04-26 2018-04-26 Charge touching device and system

Publications (1)

Publication Number Publication Date
CN108321766A true CN108321766A (en) 2018-07-24

Family

ID=62895412

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810391912.4A Pending CN108321766A (en) 2018-04-26 2018-04-26 Charge touching device and system

Country Status (1)

Country Link
CN (1) CN108321766A (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080186172A1 (en) * 2007-02-01 2008-08-07 Paul Thompson Intrusion detection system for electric fences
JP2010230996A (en) * 2009-03-27 2010-10-14 Systec:Kk Operator education system for preventing electrical accident
CN105702141A (en) * 2016-04-21 2016-06-22 国网江苏省电力公司职业技能训练基地 Live trimming body feeling system
CN208241302U (en) * 2018-04-26 2018-12-14 广东电网有限责任公司 Charge touching device and system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080186172A1 (en) * 2007-02-01 2008-08-07 Paul Thompson Intrusion detection system for electric fences
JP2010230996A (en) * 2009-03-27 2010-10-14 Systec:Kk Operator education system for preventing electrical accident
CN105702141A (en) * 2016-04-21 2016-06-22 国网江苏省电力公司职业技能训练基地 Live trimming body feeling system
CN208241302U (en) * 2018-04-26 2018-12-14 广东电网有限责任公司 Charge touching device and system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
杨宝兰;: "利用案例讲解与创新实验开展电气安全课程教学", 实验技术与管理, no. 10, 20 October 2012 (2012-10-20), pages 135 - 138 *

Similar Documents

Publication Publication Date Title
CA3022248C (en) Method and detection device for detecting a high-impedance ground fault in an electrical energy supply network with a grounded neutral point
CN103592537B (en) Electric line fault AC impedance follows the tracks of determining method fast
CN104779604B (en) A kind of neutral-point grounding resistance cabinet
CN103441483A (en) Lightning arrester device
CN103682988B (en) Spark discharge gap triggering device and method for series compensation
HRP960518A2 (en) Surge arrester
CN203415061U (en) Intelligent electrical fire hazard monitoring device
CN103650277B (en) The supervising device of electrical network, photovoltaic system and operation method for the insulation structure of photovoltaic system
CN208241302U (en) Charge touching device and system
CN102737797A (en) External lithium battery protection PTC device
CN108321766A (en) Charge touching device and system
CN204517394U (en) There is the lightning protection device of self-checking function
CN206040559U (en) Circuit breaker
CN206772352U (en) A kind of cross interconnected case for detecting cross interconnected section and case internal fault
CN202564919U (en) Electric leakage protection device
CN205901293U (en) Over -voltage protector
CN207518943U (en) Safe connection structure between circuit board
CN105661955A (en) Anti-creep express cabinet
CN206818822U (en) A kind of underground electrical equipment grounding monitoring and controlling system
CN206164089U (en) Surge protection device with high performance preventing arc cover arc extinguishing
CN205452939U (en) Transformer protection architecture
CN203165986U (en) Short-circuit protection device of battery and battery component
CN103236381B (en) A kind of type of resistance to surge Thermal Cutoffs
CN108321562A (en) Ensure safety denotable discharging rod
CN208797611U (en) One kind is for electric car charging pipette tips overheat protector and route anti-theft circuit

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination