【 Weak current College 】 vacuum pump features category---Power By 【 China power house network 】

Those taken out from the device, the device of internal gas reach vacuum machinery known as vacuum suction machine or vacuum pumps.
Structurally the vacuum pump can be divided into: reciprocating vacuum pump, rotary vacuum pumps and water jet vacuum pump, etc.

1, reciprocating vacuum pumps. Reciprocating vacuum pumps for pumping and not containing solid particle, non-corrosive gas. This vacuum pump's suction rate is large, the higher vacuum. It is widely used in the chemical plant. But its structure is complex, the amount of maintenance.

2, water ring vacuum pump. Water ring vacuum pump is a rotary vacuum pump.

3. Jet vacuum pump. Jet pump is the use of a pressure higher working fluid for the transmission of another fluid.

Circulating water pump is widely used in distillation, evaporation, crystallization, filter, vacuum, sublimation, low-temperature cooling circulating water pump is a vacuum pump and the combination of low-temperature cooling pump. That is, you can vacuum and can provide low-temperature cooling circulating water, vacuum distillation and vacuum concentration of good auxiliary equipment, the special adaptation is equipped with a rotary evaporator, which not only reduces the use of space, and reduces the vacuum, saving water, is widespread in modern laboratory equipment.

Weak current College】 【automatic door common failure and troubleshooting.

First of all here to talk about is the automatic door sensors (Pan, automatic valve) pseudo fault, which is the result of external factors on the symptom, not the machine parts. If this is false, you own is very easy to fix; of course, if the judgment is host internal electrical or mechanical problems, we recommend that you contact the dealer from them as you are responsible for troubleshooting, and replacement parts, this is because each manufacturer has private each manufacturers and other manufacturers of accessories, products are not compatible.
A common pseudo fault: door stops running (fixed) * first to see if there is power to the automatic valve unit *.
1. check whether there is a moving door leaf mopping phenomenon, if it has this phenomenon, the door is difficult when it starts, the main controller for impaired while running protection role of door leaf stops running.
2. check the door leaf of Sling pulley parts are shedding from orbit, if it has this phenomenon and crew will walk; General who has happened (objects) and the door leaf impact, often appears this fault.
3. Please pay attention to induction of automatic door is installed on the "security light", due to security light light on dust cover can also cause malfunction, so that there is an automatic menzhu control incorrectly identified as objects in the middle of the door leaf to stop the door, not move.
Common pseudo failure II: door leaf do not stop switch
1. There may be activities objects into the sensor induction range, such as pedestrians, vehicles, colorful, potted plants and other things, even light reflection may cause malfunction of the sensor.
2. check induction probe to see if induction probe for the detection range is too down, causing the door is closed, the sensors and sensing to move the door leaf, the sensor unit for objects in the movement, and the door leaf to open again.
3. a detailed check induction automatic door there is no object to issue strong waves, because of the strong waves is also possible to make the sensor interference, taken as a result of incorrect operation.
4. check on the beam is of stainless steel cover, because if dithering cover jitter will make in the above sensors with jitter, resulting in sensors produce malfunction, do not stop switch door leaf.
Three common pseudo fault: door leaf moving sounds great, not smooth (this failure often at used longer auto-sensing door)
1. door leaf of Sling pulley for the long run but has some wear, if there is a slight wear, you can track and wheel once clean (clean up dirt track); you can also add to the pulley bearings a little Lube, but be careful not to automatic door tracks and pulley surfaces add lubricating oil, because oil is easier to add the track stick on dust, so that the wheel damage faster; and prone to slipping spreader pulley, hit the door.
2. check the automatic door hardware, such as partial Sling Sling joints loose phenomenon, simply back reinforcement.
3. check the bottom of the door leaf to wheel (only damper), such as loose or damaged also occur loud, reinforcement or replaced.
Four common pseudo fault: Mobile door leaf response slow
1. sensor detection range.
2. sensor internal dust, just need to clean the sensor.
3. move the door leaf of door weight exceeds the automatic door motor bearing, can also cause this phenomenon

【 Weak current College 】 drainage construction drawing examination of points

1 construction and drainage professional relationship with interested parties
1.1 professional design, the relationship between each other
(1) the location of the electrical equipment and water supply (electricity) and control location, capacity match. Spare parts and control equipment can meet the requirements.
(2) electrical wiring, plumbing, ventilation, air conditioning installation location and move toward each other without interference. Buried pipe or conduit and cable Groove no contradiction between.
(3) connect devices to electrical wiring, control lines, pipes (water, oil and gas) road and equipment into the line to take over the position of the match.
(4) water, electricity, gas and wind pipe or a line in the installation of convergence regions and construction sequence is clear.
(5) the internal layout of the well pipe is reasonable, there is no contradiction in and out of the pipeline.
(6) various types of installation, debugging, testing, testing whether the clear relationship between the tie, with or without affecting each other.
1.2 drainage pipe installation and building relationships
(1) reserved, embedded location and install the actual need to match.
(2) equipment base location, size, elevation meets the needs of pipe laying.
(3) pipe Groove position, size, elevation meets the needs of pipe laying.
(4) building Elevation datum points and put the line basis position is clear.
(5) drainage, fire fighting pipe laying position and elevation of the building, structure, dimensions, and so there is no location.
(6) the building design. If the main structure, walls, ceiling and doors position structure structure, internal and external decoration materials and installation are no contradictions.
2 construction drawing examination of points
The water supply and drainage, fire fighting, civil defense Engineering Service Tribunal figure of several major principles and varies according to the drawings directory are described below in points.
The principle of trial 2.1
(1) design meets the relevant technical policy and standards and the building design documentation prepared depth requirement.
(2) drawings information are complete. Ability to meet construction requirements.
(3) design is reasonable. There are no omissions. A drawing of the mark have no errors. Relevant channel number, device model is complete and correct. The relevant parts of elevation, slope, coordinates of the location is correct. Material name, specifications, quantity is correct and complete.
(4) design specification and design of the technical requirements are clear. Design meets the conditions for the construction and equipment of enterprises. If you need to take special measures. There is no difficulty in technology. Can you guarantee the construction quality and construction safety.
(5) design intent, engineering characteristics, equipment, facilities and control process. Technological requirements are clear. The design is clear. Compliance process and technology requirements.
(6) for pipeline installation location is beautiful and easy to use.
(7) pipe, components, equipment, technical characteristics, such as pressure, temperature, medium is clear.
(8) on the fixed, vibration, thermal insulation and corrosion, heat insulation and use of methods, materials, construction technology requirements and paint color provision is clear.
(9) requires the use of special construction, construction tools, construction machinery parts requirements and practices are clear.
(10) there are no special material requirements, specifications, variety, quantity can meet the requirements, there is no possibility of substitute materials.
2.2 instance map points
2.2.1 General description
(1) design description should include the design basis, design, supply and drainage, fire protection systems and to the point of recited, tubing and connectors, valves and valves, pipe laying, pipeline pressure and corrosion-paint, piping and equipment insulation, etc.
(2) the main equipments, materials table water pumps, water treatment equipment, water heating, cooling, fire-fighting facilities, health apparatus, whether or not the security model.
(3) pipelines, equipment, anti vibration, noise, water hammer, settlement expansion, expansion, the prevention of pollution, prevention of dew, Frost, gas discharge, fixed, insulation, inspection, maintenance, etc. are to take effective and reasonable measures.
(4) whether the requirements of the fire code for setting the fire hydrant, fire sprinkler, fire extinguishing, water sprinkler, fire extinguishers and other fire safety systems and facilities, water requirement is justified.
(5) whether the use of outdated products.
2.2.2 to the row level and figure
(1) living pool, water tank is independent of the structure type.
(2) water supply piping and water heating equipment and may lead to the return of sanitary connections are there measures to prevent backflow contamination.
(3) position of the domestic water supply pumping stations are avoided with anti-vibration or have a quiet room on request. Pump, suction and pressure pipe bracket and engine room wall roof taken measures vibration or noise.
(4) there are no toilets. Bathroom layout in the restaurant, food processing, storage and distribution equipment, strict hygienic requirements of the upper House.
(5) underground sewage pump shaft is set to seal well cover and snorkel.
(6) selection of water heating equipment and its layout, laying is considered maintenance requirements.
(7) in the laying of pipeline layout, meet regulatory requirements.
2.2.3 water fire protection, civil defense section plan
(1) building in different rooms or public fire fighting facilities choice is appropriate, for any omission.
(2) fire water tank, high water tank and fire pump house meets specification requirements.
(3) fire hydrant and automatic sprinkler head, pump adapter layout meets specification requirements.
(4) requires the water curtain partition or meet fire curtain partition Department whether the regulatory requirements set by the water facilities.
(5) whether the fire elevatorSet the drainage facilities.
(6) the cold regions. No heating in the underground garage has frozen the fire water pipe may be whether there is reasonable and practicable measures antifreeze.
(7) the shape of fire extinguishers and arrangement meets specification requirements.
(8) when someone or basement. Drainage design should be consistent with the relevant norms of civil defense design and the locals against the requirements of the competent authorities.
2.2.4 General layout
(1) fire private or domestic use of outdoor water supply pipe is according to the specifications in a pipe. Fire hydrant, pump adapter layout for conformance to specifications.
(2) in municipal sewage, storm drain junction wells of pipe diameter and elevation are appropriate.
(3) septic tank, cesspools, etc and buried water cisterns of distance is not less than 10m. when not met. Are taken to prevent contamination of water reservoir water of effective measures.
2.2.5 system diagram
2.2.5.1 water supply system
(1) high level and low level architecture of water zones for conformance to specifications, most do not use water pressure can be guaranteed.
(2) water supply piping connection exists backflow contamination problems.
(3) water tank, water tanks to the point of drinking water supply pipe is complying with the provisions adopted secure a pollution prevention measures.
(4) in accordance with the regulations required for the entry in the water, is set out in the water treatment and water supply system, water is in the water balance.
2.2.5.2 hot water system
(1) whether the hot-water supply and water partition partition, hot water supply pressure with cold water pressure balance, (separate use cold water or hot water except).
(2) where the hot water supply system is set up effective circulation system, hot water system for high-rise buildings with pressure relief valve when partitioning the circulatory system can guarantee the normal work.
(3) whether a public bathroom equipped with temperature stability and water-saving measures.
(4) system is used for the expansion pressure relief valve, expansion pipe (or expansion tank), expansion joints, fixation, and other accessories. Is there to prevent and alleviate pipeline and equipment-scaling, corrosion of the equipment.
2.2.5.3 drainage system
(1) drainage system for rain, dirt and rain bucket diversion; layout of compliance.
(2) sewage standpipe bottom horizontal drainage pipe connection meets specification requirements. Or take out home alone.
(3) water pipes is according to the specifications set snorkel and checkpoints, sweeping mouth.
2.2.5.4 fire protection system
(1) fire water tank and water in the roof fire water tank volume compliance. When fire, life combined with pools, water tanks. There is no guarantee that water is not passive fire protection measures.
(2) fire meets specification requirements. System for vacuum, pressure relief, safe use and ensure the effectiveness of measures for fire. There are no measures of the post of fire pumps.
(3) fire pumps and booster equipment meets specification requirements.
(4) whether indoor hydrant network specifications into the ring. The service pipe pipe is not less than two. Pipe arrangement of hydraulic network meets specification requirements.
(5) the roof is set test fire hydrant. Automatic sprinkler system layer is there at the end of the Terminal on the water test device.
(6) fire hydrant and sprinkler off water system pipe diameter is justified.
(7) the cold regions, and not whether the heating, garage, BU using dry or preaction sprinkler system.
(8) fire pump adapter settings meets specification requirements.
3 construction drawing examination of figure considerations
(1) see the master plan is to audit whether total design water consumption. As well as the local average water pressure and the selection of pipe diameter fits. As well as the cleanliness of water quality. To consider the accumulation of scale to reduce the occurrence of pipe flow. Therefore, the total intake duct should increase the level of water consumption basis. To check the pipe and other pipeline or building has no effect and impede the construction. Whether you need a diversion.
(2) in view of the construction drawing unit project. Mainly water system perspective. In auditing settings for the major check pipes are reasonable. Water meter settings location is easy to check and repair. To local service when the control valve. Configuration of health apparatus is economical and reasonable.
(3) for a large public buildings, water supply and construction of high-rise buildings. You want to audit for any separate fire water system. But it cannot be mixed in the general use of water piping it should have a single valve wells, separate pipe, single valve. Place the valve shaft position is less open and close. Is less maintenance. There are no obstructions around. To ensure that fire when the emergency use.
(4) on the design of the drainage pipe, materials, drainage system compatible health apparatus. When can the Tribunal figure on the pros and cons of using a material to raise questions or suggestions. For design or use of the unit of reference.
(5) according to the usage of auditable pipe diameter size is appropriate. As some public toilet because current use conditions and the staff of the complex. Its sewage standpipe diameter cannot be as usually several dunwei. Sometimes design of tube diameter DN100. Often need to increase to DN150. use only. Not be blocked.
(6) on drainage in the outdoor section. Whether the principal is pipe slope. The adequacy of the gradient. Sewage pipe bends the confluence is set to check well. Its depth is sufficient. You should also note the location of the manhole. Whether it will pollute the environment and affect vulnerability to contamination of underground structures.
(7) construction and drainage construction drawings to check each other's content is largely elevation. Lower level rooms using the same function. Prevent the upper room to kitchen and bathroom. The lower part of the housing. This damage to the room's perfect. Once the above Division of water leakage between the kitchen and bathroom. Would seriously affect the lower roomUse. At the same time to prevent the outer riser set to balcony. Both inconvenient and install even more important is the impact on appearance.
(8) to drain through beam is in some parts of the body affects the structure. Because of the drain through the beam pipe to occupy a position. The beam section. Weaken the beam's intensity. Especially the balcony outside the root of the cantilever beams. Drain through are not allowed. Otherwise there is no guarantee that the intensity of the cantilever. Leave a security risk.
4 closing
Construction drawing triage is a very detailed technical work. Its comprehensive strong. Good drawings to be audited. In addition to examining figure who seriously look at the pictures. Also with the Tribunal's own quality related graphs. Audit diagrams ' comprehensive quality. Including the ability to design look; the related design and construction specifications of understanding and awareness; on construction technology and construction method sites experience; knowledge of building and structure; on the edge of the water supply and drainage professional relevant professional knowledge; construction equipment construction and a variety of cross-channel integrated layout in collision avoidance. As long as we in engineering practice to continually improve the knowledge and skills. We will be able to improve the audit plan. More pro-active solution to construction drawing problems in ensuring the quality of the project.

Weak current College】 【self-priming classification and working principle.

1. self-priming concepts and classifications:

1. self-priming pump is not required in the pipeline filled with water inhalation can automatically put water pumping up called self-priming centrifugal pumps. Most of the internal combustion engine supporting the merits of self-pumping pump, mounted on a movable carriage, appropriate for field work.

2. self-priming structure types are divided into two kinds: mixed-type self-suction pump and intermixing of suck.

2. self-priming works:

1, mixed-type self-suction pump works: pump start before pump shell inside filled with water (or pump case is water within itself). Startup impeller rotating impeller rotation channel in streamwise Vortex shell, then the entry form, into the vacuum backstop doors open, air suction tube into the pump and impeller channel arrives at the outer edge. On the other hand, the impeller to gas and water separation Chamber of water by left backwater hole on the outer edges of the stream back to the impeller. Left backwater hole flow back into the water in the pressure difference and gravity, the impeller grooved, and impeller smash, and the inhalation of air pipe to the left to scroll the flow to the direction of rotation. And then with the right return water hole streams to the convergence of the water, along the spiral flow. Since the liquid in the volute continually impact Cascades, constantly being smashed the impeller, mixing with air strongly, generating gas-water mixture, and continually flows cause gas water cannot be separated. Mixture in a snail shell export was divided tongue split along the short tube into the separation Chamber. In the separation of indoor air is separated by the pipe the water drain, while still having left backwater hole to the outside edge of the impeller and the mixture of air suction tube. So repetition, gradually the inhalation of air exhaust in the pipeline, so that the water pump, complete self priming process.

2, intermixing of self-priming, working principle and external mixing suck the same, the difference is the backwater does not flow to the outer edge of the impeller and the entrance to the impeller. Intermixing suck at startup, open impeller directly below the return valve before, so that the pump impeller of liquid flow back to the entrance. Water in the role of the high speed rotating impeller with suction tube to the mixture of air, gas and water mixture flows into the separation Chamber. Here the air emission and water from the return valve to return to the impeller inlet. So repeatedly until air discharge and suction on the water.

Self-priming pump's suction height, front impeller and seals, pump speed, separation Chamber surface height and other factors. Front impeller seal smaller, larger suction height, generally take 0.3 ~ 0.5 mm; in the gap increases, in addition to suck the height drops, the pump head, efficiency is reduced. Pumps suck the height with the impeller of u2 's circumference speed grows, but the biggest suck the height, speed increase and suck the height is not increased, at this point just shorten suck time; when the speed drops to suck the height as the fall. In other conditions unchanged, suck the height also with water height increases (but do not exceed the separation Chamber of best water height). In order to suck the pump by oneself better in the air-water mixture, the impeller blades required less, make the pitch increases Cascades; and the use of half-open impeller (or impeller channel wide impeller), which is more convenient to return water deeply into impeller blade.

【 Weak current College 】 household central air conditioner buying tips, installation progress reference process

STEP1 develop preliminary renovation plan.

Don't miss the best of central air conditioner installation time

And conventional air conditioning installation methods, design of residential central air conditioning in the rooms of the installed best decor design domestic central air-conditioning before! is the adoption of the "hidden" install mode, its design installation scenarios to overall decoration of the housing programme, otherwise it will have an impact on late-stage decoration. For example, the host can use ceiling (even including the bathroom ceiling) will host the "hidden", so that the overall pattern of housing will be more simple and elegant. Therefore, please be sure to immediately inform decoration designer you have to install a central air conditioning plan.

STEP2 selected brands.

A good brand, not only is the product quality guarantee is a guarantee of service

Household central air conditioner is durable consumer goods, simultaneously also is a "semi-finished", because it combined with the interior decoration. To make a set of domestic central air conditioning system to function properly, the design, installation, construction of the importance of the machine. The following is a selection of domestic central air conditioner brand, you need the key considerations:

Be sure to select the service good, reputable brand to protect their own interests.

Now that is a home with air conditioning, natural to choose a professional manufacturer of residential central air conditioning. And professional development for shopping centres, factories, hotels, etc. larger commercial establishments of manufacturers of commercial central air conditioning, a professional manufacturer of residential central air conditioning in product development, will be more focused on the air conditioning in the energy-saving power, comfort and ergonomic aspects. In addition, there are strong technical development strength, can we truly and matches the "professional", is the best quality and service.

The so-called "third product, seven installation" refers to the central air-conditioning use is good or bad, depends on product quality, design, installation, commissioning, after-sales service, and other aspects. Therefore, choosing a good brand, you also need to have a professional sales installation company. In General, manufacturers specify sales installation company, is your best choice. Because manufacturers will be the system of training, at the same time, the specified sales installation company, also on the brand of product performance, installation requirements, have a deeper understanding, so their installation technology will become more professional, but also more security services.

STEP3 developed air conditioning programme.

Home decoration tips

The ability of domestic central air conditioning, models, the return of air supply mode, remote control, installation location, and so on, are required depending on the room type and user needs and features to develop design decoration. For example: remote control of the way in both wired and wireless, living-general staff to walk more, you can select wired remote control, flexible operation, little bedroom, you can select wireless remote control; in addition, to develop a good air conditioning, air conditioning architects, interior designers and users to third parties full communication is also very important.

Early communication is important. To provide air conditioning designers real-time decoration scheme, all rooms feature distribution information, and as far as possible decoration designers communicate with air-conditioning designers. The model selected. After the above steps, the air conditioning system designers can calculate a air conditioning load value, according to the load value, selected indoor and outdoor machine. Of course, the final selected models, you also need to combine the characteristics of regional climate, the housing itself storey, direction, heat and other factors to consider.

Design the way back to the wind. That is, the air, wind patterns and ceiling moulding on effectively to ensure air conditioning effect, but also guarantees that the House is beautiful. If the ceiling space is large enough, you can use side sent back after; if the ceiling is not enough space, you can use the spacious side sent next time; if you do not consider ceiling form, you can consider using the toilet, and other adjacent space made way back side songce. In addition, reasonable arrangement of the diffuser is also important to take care of the air distribution to all the corners of the room and, more to avoid supply outlet on direct blowing.

Construction design. Apart from the design process, sales will also install the company planned the entire construction design, for example: in order to ensure the effectiveness of the refrigeration, heating, construction design should minimize refrigerant piping length; installed refrigerant piping, you need to have some space left tube and try to avoid wearing beam; drain, condensate pipe should follow the principle of water nearby.

Site survey to determine the final design for air conditioning. Designers and your onsite field survey, the characteristics of your House, installation conditions, air conditioning, power supply

STEP4 contract.

Home decoration tips

To protect your legal rights, you should install the company signed a sales contract of sales. And, to ensure that your progress and duration of decoration, in the decoration beginning 1 ~ 2 weeks before signing the contract, the company is ready to install air conditioning sales and installation materials sufficient period of time. Also, be sure to set aside a certain amount of quality security deposit, in order to safeguard their rights at the time of acceptance.

STEP5 air-conditioning equipment and installation personnel.

Home decoration tips installation considerations

The installer must undergo professional training, there are manufacturers recognised to construction operations.

Indoor lifting, pipeline arrangement, etc., can and other "secret project" hand in hand.

Indoor installation: installation, you must check the model number, name, and whether they are consistent with the design. The installation process, you must accurately locate its installation location, and ensure the level of the installation, to reduce running noise. In addition, indoor Suspender nut anti-loosing measures must exist, and we assure the installation of a security firm. Indoor installation, application of plastic bags, and other decorative unfinished front, not open the plastic bag to prevent dust, otherwise affect future results. Finally, we must pay particular attention to, it is critical that you stay in a outlet for later inspection and repair.

Laying of pipeline: refrigerant pipesAnd drainage pipes, pipe fittings, valves and pipeline are metal parts in contact to insulation wrapped to prevent condensation water dripping, impact of smallpox and other local housing decoration. Copper pipe laying is complete, you must perform pressure and leak test.

Installing outdoor unit: first, to wall drilling, with special attention to prevent rain penetration, pipe through the outer wall must be sealed at the same time in the drilling Department set protection casing; second, the system for vacuum drying, to avoid cooling-performing or system of phenomena such as ice barrier; third, the outdoor unit installed locations to sophisticated cooling ventilation, easy maintenance, at the same location where you want to try to hide, to avoid affecting the House look and noise impacts indoor.

In the outdoor unit around or stand around must be equipped with drainage channels, especially on the roof platform installed, you must pay attention to the waterproofing roof construction, guarantees not leak. Fourth, as the outdoor unit of the fin is exposed on the outside, easily hurt, thus affecting the appearance and use effects, so great care should be taken when installed, such as scratches, abandoned the comb or brush comb.

STEP7 decorating.

Before the start of the decoration, the indoor and outdoor machine packed with a plastic bag to prevent dust, etc., affecting future use. And, in the whole inner decoration is in progress, do not use air conditioners or open indoor and outdoor machine plastic bags.

STEP8 installation Tuyere, final acceptance test run.

Generally a room or Hall need only one outlet, if the living room area is large, or rectangular, with a draught. If you selected the side sent the next time, pay attention to the outlet and the direction of the fan blade back outlet cannot be the same direction, so as to avoid short circuit, cooling/warming effect caused a greater impact.

Home decoration and central air conditioning works after installation, you must be a system of determination and final acceptance test operation (hereinafter referred to as acceptance). System debug at full load and minimum load conditions. Air conditioner unit test run to 1.5 hours.

STEP9.

Weak current College】 【how to do a good electronic meeting system.

<br> «Ò» ¡ .¢ first planning <br> <br> To do a good conference system must first learn how to plan a conference system. <br> <br> First: to plan a perfect smart meeting system, that has a hyper-realistic, practical projects .; <br> <br> Why is hyper-reality, is to break the previous conference room design ideas, jump out of the previous mode. In an ideal way of thinking, to propose design plan. <br> <br> First, .we want to analysis; analysis of? mainly of the customer, the customer's needs, to achieve the function, capital, boot clients. There are the following: 1. make feature; 2. scene; 3. Design highlights; 4. upgrades and .extensions; 5. maintenance; 6. cost. A complete and perfect design and solutions must be close to the user, to the needs of users for the first point of departure. To fully understand the needs of users. Analysis to design, the design .is based on a function. According to user needs, identify the functional requirements, depending on the features to build system. Design solutions in several ways: 1. at the request of the customer on system; 2. the composition of the intelligent conference system .; 3. subsystems function and composition; 4. equipment selection; 5. a list of equipment; 6. system connection diagram; 7. system implementation. <br> <br> Previously we talked about: according to build system. The system is .going to be functional, only every single function, and finally to achieve full functionality of the system. We call this system breakdown: System - subsystem - device - functionality. Now we are looking for: function - the device - subsystem - system. < .br> <br> 1. the Conference room meeting features; 2. remote video conferencing features; 3. sound; 4. display; 5. the camera function; 6. signal source management function; 7. camera tracking; 8. centrally control .function <br> <br> Digital conference system should use for the various conference rooms provide the most direct audio amplification function, audio signal transmission function, audio signal recording function, image information replay function, image information transfer function, image information logging capabilities, .multimedia processing, analog and digital information transformation uses both shared function, meeting, servo and control functions. <br> <br> Digital conference system is brand new, with advanced technology, complete, safe and reliable performance, convenient operation, easy maintenance, .etc.; shall be a mature, stable, reliable and complete system integration, its performance is excellent; equipment Typ of indicators should be consistent with national or international standards and requirements to meet the needs of all types of meetings. <br> <br .> Digital conference system is mainly designed to meet the high standards, the number of participants more multimedia discussion-Conference, at the same time satisfy the special case of external communication. Thus meeting room system integrated to the level of the international modern pop has synchronized ., advanced, open, scalability, reliability, and standards. In General, to meet the needs of modern office; in the case of local on the meet the specific of each room a different usage requirements. <br> <br> Its design scheme .to introduce a new concept, advance mental consciousness, according to the "State-of-the-art design, first-class equipment, first-class management, first-class service", asked to carefully designed programmes, functionally to meet modern, .informative and intelligent. To fully experience the same type of room at home and abroad of successful experiences, reflect the characteristics of the times. The entire system including the place of all audio and video, control system, should meet the needs of various application areas .. Programmes should be to complete the "technology, advanced equipment, complete functions, save money," is a principle, the scientific planning, reasonable layout, set aside the full application convenient features, to achieve a modern high-efficiency, comfort, safety .and energy saving at the request of the human work environment. After we design to product training. <br> <br> Second, product training <br> <br> Product training principles are as follows: 1. well-known brand; 2 .. value for money; 3. the manufacturer of comprehensive strength; manufacturers have strong comprehensive strength and can provide very strong backing. 4. manufacturers to provide support and service. Support: can price support, technical support, staff support and other services: after .sale. <br> <br> Implementation; when we have the equipment and programmes, also know the installation location. <br> <br> Next step is to consider the approach implemented. Overall, do the following: <br> <br .> Wiring requirements: strong, weak lines separately; power and signal cables separately; power and control cable separately; all conductors must wear pipe laying; the entire system with a unified power distribution box, so as not to produce power interference between devices; in .high pressure and high magnetic field and other harsh environment, you should choose the shield line; in a humid environment should use sheathed cable. <br> <br> The preceding conditions under the premise of the project's highlights will depend on the perfect debug between .devices, play the device maximum value using the installation notes and more. <br> <br> Also, a good engineering is also requires a lot of precipitation, in construction, many problems is the need of our attention, digital conference system requires a .lot of knowledge of precipitation: like the need to learn to whistle of effective treatment: sound reinforcement system usually uses the microphone gain level representing sound feedback, ideally should be the volume all the way up, still not whistling, members of the audience receives the .voice of the speaker and the microphone receives direct sound and the difference between the sound level to dB indicates audio gain level. The Elimination of whistling from the causes of the various aspects to take the necessary measures, so long as we can destroy one of these .conditions, the Suppression and elimination of whistling. <br> <br>.

College】 【weak escalators and moving walkways installation and maintenance --- Power By 【China】 weak home network.

Safety requirements for lifting operations <br> 1 1.1 lifting operations by professional personnel hoisting operations. .1.2 Lifting equipment should be made of special equipment inspection certification, rigger is required to hold the appropriate qualification certificate. .1.3 lifting, harness (rigging) of the safety factor of not less than 5, the lifting material lifting equipment should not exceed the rated load. .1.4 Lifting, the Xianzarenyuan should not close, boom stand on the following prohibited. .<BR> <BR> 1.5 before each use, all the lifting equipment shall be subject to visual check for substandard areas. .In question should immediately stop using the equipment. .1.6 pedants may shake or by limiting the area should be used when the end of rope and lead rope. .<BR> <BR> 2 2.1 security requirements the construction site before the start of work shall be escalators and moving walkways at the entrances to set an effective barrier, warning and prevention of work related personnel strayed into the area. .2.2 The maintenance operation should ensure that the escalators and no passengers on the sidewalk can stop the run escalators and moving walkways. .2.3 before carrying out the work, escalators and moving walkways in the main power switch and power switch should be placed in the "off" position, lock tab and hoisted the effective testing and validation. .2.4 When a section of steps to be removed or not allowed to take with escalators and walkways, two independent methods applied in the electrical and mechanical locking devices. .3 Truss, Safety Requirements 3.1 Test switch to stop and repair, testing the effectiveness of sharing and direction buttons. .3.2 escalators and moving walkways can only repair speed. .3.3 is not allowed to walk in the cascade axis. .3.4 the main power switch lock, alarm and take two independent methods, electrical and mechanical barrier to prevent the cascade chain movement. .4 drive station and steering station, Safety Requirements for 4.1 station turned into the drive should be the next station and stop switch. .4.2 provide sufficient lighting to ensure safe access and safe working, the control switch should be in place near each entrance. .4.3 equipped with a power outlet to use power tools to prepare. .The socket should meet the requirements of GB 16899-1997 in 13.6. .4.4 station turned into the drive station and work, should be set at the entrance to the effective protection device. .4.5 For the overloaded escalators and moving sidewalks, motor, gear box should take precautions to prevent exposure to high temperatures such equipment may reach high temperatures in the machine warning signs should be affixed..