HS code compliance in cross-border rail freight

List of the table of contents of this article:

• 1,HS code compliance in cross-border rail freight What are the ways of indoor coverage
• 2 , Which two parts of the indoor distribution system are mainly composed of
• 3, Installation and specification of the main equipment of the 5G room subsystem?
• 4, High-speed rail distributed optical fiber temperature measurement is mainly used in those places
• 5, What is the principle of the distributed optical fiber temperature measurement system?

What are the ways of indoor coverage

1. 3. Wiring For example, there is a network cable pipe from the living room to the master bedroom, the second bedroom also has a wire pipe, and the study. In this way, our pre-burial is completed. 4. Wire threading. When threading, it is generally carried out at the same time as the wire installation.When threading wires at home, insert these network cables at the same time.

2, D. Replacement station In some small and medium-sized shopping malls and restaurants where the capacity requirements are not very high, the re-release station is an economical and practical solution E. Large-scale indoor coverage - optical fiber distribution system For large-scale indoor coverage systems, the distribution antenna will reach hundreds of payments. If the power distributor is used, the loss will become unacceptable.

3. There are three main ways to achieve indoor coverage: (1) Indoor coverage in the coverage area is provided by outdoor macrocellular at the same time. This method is still the main method in China at present.

Which two parts are the indoor distribution system mainly composed of

The indoor distribution system is mainly composed of two parts: the giver source and the signal distribution system from various system networks. The main source includes base stations, base station remote equipment, wireless or wired relay equipment. The indoor signal distribution system is composed of active devices, passive devices, antennas, cables, etc. The system structure is shown in Figure 10-27.

Room division (indoor distribution system) is for indoor user groups,A scheme that mainly solves the network coverage, network capacity and network quality of the mobile communication network in the building. It is the main network optimization method for covering indoor signal weakness and signal blind spots.

The project of Room G is used by China Telecom Group Co., Ltd., China United Network Communications Group Co., Ltd. and China Radio and Television Network Co., Ltd. Indoor distribution refers to a signal coverage method that introduces the base station signal into the room to solve the problem of indoor blind area coverage.

The indoor coverage system consists of two parts: signal source → signal distribution system. The function of the signal source: to provide wireless signals for the indoor coverage system.

The indoor distribution system is mainly composed of three parts: signal source equipment (microcellular, macrocellular base station or indoor retator station); indoor wiring and its related equipment (coaxial cable, optical cable, leakage cable, electric terminal, optical terminal, etc.);Trunk amplifiers, power dividers, couplers, indoor antennas and other equipment.

Installation and specification of the main equipment of the 5G room subsystem?

1. The new digital room division system mainly uses optical fiber and network cable to transmit digital signals, supports high-frequency bands, which is conducive to the smooth transition to 5G. At the same time, the new digital room division system takes MIMO into account when designing. At present, the equipment supports 2T2R by default, and can be upgraded to 4T4R by software control.

2. Whether the installation position conforms to the specification: It is necessary to check whether the installation location of the equipment meets the specification, including the height, distance and object cover of the equipment, to ensure the stability and communication performance of the equipment deployment.

3. Master the method of checking the installation environment of EMB5116 main equipment.Master the usage of installation tools and instruments. Learn to fill in relevant documents. Recognize the security symbol. Master the main equipment system mechanism of the base station. Master the installation of the main equipment of the base station. Practical training steps: check the equipment installation space in the computer room.

4. The g-chamber subsystem mainly includes commonly used device resistors, capacitors, diodes, triodes, controllable silicon, light-touch switches, liquid crystals, light-emitting diodes, buzzers, various sensors, chips, relays, transformers, varistors, fuses, optocouplers, filters, plugs Parts, motors, antennas, etc.

5. Installation of battery equipment Composition of communication base station power supply system Communication base station AC power supply system Communication base station DC power supply system Storage battery Remote power supply Composition of base station AC power supply system Base station requires the introduction of more than one mains power supply.

High-speed rail distributed optical fiber temperature measurement is mainly used in those places

1. It is mainly used for temperature measurement in oil depots, coal mines, arsenals, underground shopping malls, tunnels, large and medium-sized transformers and cable trenches, etc., and can Temperature alarm is achieved by monitoring temperature changes.

2. Distributed optical fiber temperature measurement host system (dts) (1), use: tunnel fire monitoring, subway and high-speed rail fire monitoring, power cable temperature monitoring, crude oil, natural gas pipeline leakage monitoring and other fields. ( 2). Introduction: Distributed optical fiber temperature sensing system (dts) is a real-time, online and continuous online temperature monitoring system.

3. Another type of application occasion is all kinds of highVoltage devices, such as generators, high-voltage switches, overload protection devices, and even overhead power lines and underground cables. The production process of flammable and explosive materials and the temperature measurement of equipment. Optical fiber sensors are essentially fireproof and explosion-proof devices. They do not need to adopt explosion-proof measures and are very safe and reliable.

4. The principle of optical fiber temperature measurement is to convert temperature changes into optical signals for measurement. The method of use is to inject a high-power laser into the optical fiber, and the light intenss scattered back will change over time. The temperature change is determined by measuring the change of optical signals. Optical fiber temperature sensor is a new type of temperature measurement technology developed in the 1970s.

5. The whole system adopts optical fiber as the carrier for sensitive information sensing and signal transmission, with continuous temperature measurement, distributed temperature measurement, real-time temperature measurement,It has the characteristics of anti-electromagnetic interference, intrinsic safety, remote monitoring, high sensitivity, easy installation, long service life and so on.

6. In the power system, it is necessary to measure temperature, current and other parameters, such as temperature detection in the stator and rotor of high-voltage transformers and large motors. Because electrical sensors are susceptible to electromagnetic field interference, they cannot be used in such occasions, and only optical fiber sensors can be used.

What is the principle of the distributed optical fiber temperature measurement system?

1. Distributed optical fiber temperature strain monitoring technology is based on the principle of optical fiber sensing, and uses optical fiber as a sensor to measure temperature and strain. Optical fiber sensors usually adopt optical fiber Bragg grating (FBG) or Raman scattering technology to infer the distribution of temperature and strain by measuring the optical signal changes of optical fiber sensing elements.

2. The principle of optical fiber temperature measurement is to convert temperature changes into optical signals for measurement. The method of use is to inject a high-power laser into the optical fiber, and the light intenss scattered back will change over time. The temperature change is determined by measuring the change of optical signals. Optical fiber temperature sensor is a new type of temperature measurement technology developed in the 1970s.

3. Distributed optical fiber temperature measurement system (DTS), also known as optical fiber temperature measurement, is based on the principle of optical time-domain reflection (OTDR) and the sensitivity of Raman scattering effect to temperature to achieve temperature monitoring.

4. DTS, the full name of the distributed optical fiber temperature measurement system, is a temperature measurement system generated according to the principle of the temperature effect of optical fiber back to Raman scattering, which can detect the temperature of different positions along the optical fiber.Degree change to realize real distributed measurement. In the system, the optical fiber is both a transmission medium and a sensing medium, which is not subject to electromagnetic interference and has high measurement accuracy.

5, L·℃); λS, solid thermal conductivity (E/s·L·℃); cS, solid specific heat (E/M·℃).

6. The main working principle of the distributed optical fiber temperature sensing detection system is the optical time domain reflection technology (OTDR) and the backward RAMAN SCATFORING temperature effect of the optical fiber. The distributed optical fiber temperature sensing system uses advanced OTDR technology for positioning and the Raman scattering effect to measure temperature.