Weak current engineering is a classification of power applications. Electric power applications can be divided into two categories based on the strength of the transmitted power: strong electricity and weak electricity. The power consumption of buildings and building complexes generally refers to weak current with AC voltage below 220V 50Hz. Mainly providing people with electric energy and converting it into other energy sources、 such as air conditioning、 lighting、 power、 and so on. The commonly used building weak current systems for system functions mainly include the following: (1) telephone communication systems achieve telephone (including three types of fax machines、 video phones、 etc.) communication functions; Star topology structure; Use Class III (or above) unshielded twisted pair cables to transmit signals at frequencies within the audio range. (2) The computer local area network system is the network foundation for achieving office automation and various data transmission; Star topology structure; Use Category 5 (or above) unshielded twisted pair to transmit digital signals、 with a transmission rate of over 100 Mb/s. (3) The music/broadcasting system plays music through speakers installed on site (such as shopping malls、 stations、 restaurants、 guest rooms、 corridors、 etc.)、 and can broadcast on site through microphones; Multi channel bus structure; Transmit a constant voltage (such as 120 V/120 Ω) audio signal output by a power amplifier to drive the on-site speaker to produce sound. The transmission line uses copper insulated wires. (4) The cable TV signal distribution system evenly distributes cable TV signals to various user points in the building; Using branching devices and distributors for signal distribution、 in order to reduce signal distortion and attenuation、 and ensure that the signal quality of each user point meets the requirements of the specifications、 the wiring is a tree structure、 which varies depending on the form of the building and the distribution of user points; Use a 75 Ω RF coaxial cable to transmit multiple RF signals. (5) The video surveillance system monitors various entrances and exits of buildings and some important places through equipment such as cameras and anti-theft detectors installed on site、 and alarms for abnormal situations; The transmission of video signals adopts a star structure and uses video coaxial cables; The transmission of control signals adopts a bus structure and uses copper core insulated cables. (6) The fire alarm system consists of three parts: fire alarm and fire linkage system、 fire broadcasting system、 and fire alarm intercom telephone system. The fire alarm and fire linkage system monitors the on-site situation through fire detectors、 manual alarm devices、 etc. installed in various parts of the building. When there is an alarm signal、 according to the received signal and the predetermined program、 the corresponding equipment is linked to control the spread of the fire. The signal transmission adopts a multi-channel bus structure、 However、 for the transmission of linkage control signals for important firefighting equipment (such as fire pumps、 sprinkler pumps、 positive pressure fans、 smoke exhaust fans、 etc.)、 sometimes a star structure is used、 and the transmission of signals is carried out using copper core insulated cables (some products require the use of twisted pairs). The fire broadcasting system is used to command the safe evacuation of on-site personnel in the event of a fire、 and adopts a multi-channel bus structure. The signal transmission uses copper core insulated wires (this system can be used in conjunction with music/broadcasting systems). The fire alarm intercom telephone system is used to command on-site firefighters to carry out firefighting work. It adopts two structures: star and bus、 and signal transmission uses shielded wires. (7) The entrance and exit control system/one card system uses devices such as computers、 smart card locks、 and card readers to set、 monitor、 control、 and record the status of each entrance and exit、 achieving unified management of each entrance and exit of the building and ensuring building safety. Its topology and transmission medium vary depending on the product. (8) The parking lot toll management system senses the entry and exit of vehicles through induction coils installed below the entrance and exit ground. Through manual/semi-automatic/fully automatic toll management systems、 it achieves toll collection and controls the opening and closing of electric railings. The wiring of this system is limited to the entrances and exits of the building parking lot. Each entrance and exit is controlled by a controller、 which can work independently or be connected to the upper management computer. The wiring structure and transmission medium vary depending on the product. (9) The building automation system detects、 monitors、 and controls various environmental parameters inside and outside the building、 as well as the working status of various equipment inside the building (such as air conditioning、 water supply and drainage、 lighting、 power supply and distribution、 elevators、 etc.) through various detection and execution devices connected to the on-site controller. It also connects to various on-site controllers through a computer network to reasonably allocate and manage resources and equipment inside the building、 achieving comfort、 convenience、 and economy Reliable purpose. There is no international standard for building automation systems、 and the communication protocols used by different manufacturers' products are different. The topology and transmission media of their field bus and control bus are also different. Below is a brief introduction to LonWorks technology and BACnet technology、 which are widely accepted and adopted by the international community. In addition、 there are video conference systems、 screen display systems、 sound reinforcement systems、 patrol systems、 building intercom systems、 and automatic meter reading systems for three meters (water、 electricity、 and gas). Buildings with different functions require different weak current systems to be installed

Function of testing report:

1. Project bidding: Issue authoritative third-party CMA/CNAS qualification report

inspection and testing process:

1. Telephone communication and confirmation of requirements

Testing and testing characteristics:

1. The testing industry is fully covered、 meeting different testing needs

3. Engineers provide one-on-one services to make testing more accurate

4. Free initial testing、 with no testing fees charged

5. Self service order delivery for free on-site sampling