Steel that is resistant to corrosion from weak corrosive media such as air, steam, and water, as well as chemical corrosive media such as acids, bases, and salts. Also known as stainless acid-resistant steel. In practical applications, steel that resists corrosion from weak corrosive media is often referred to as stainless steel, while steel that resists corrosion from chemical media is referred to as acid-resistant steel. Due to the differences in chemical composition, the former does not necessarily resist corrosion from chemical media, while the latter generally possesses stainless properties. The corrosion resistance of stainless steel depends on the alloying elements contained in the steel. Chromium is the essential element that gives stainless steel its corrosion resistance. When the chromium content in the steel reaches about 12%, chromium reacts with the oxygen in the corrosive medium to form a very thin oxide film (self-passivation film) on the surface of the steel, which can prevent further corrosion of the steel substrate. In addition to chromium, commonly used alloying elements include nickel, molybdenum, titanium, niobium, copper, and nitrogen, to meet the requirements of various applications for the structure and performance of stainless steel. Stainless steel is usually classified according to its matrix structure: ① Ferritic stainless steel. Contains 12% to 30% chromium. Its corrosion resistance, toughness, and weldability improve with increasing chromium content, and its resistance to chloride stress corrosion is superior to other types of stainless steel. ② Austenitic stainless steel. Contains more than 18% chromium, about 8% nickel, and small amounts of molybdenum, titanium, nitrogen, and other elements. It has good comprehensive performance and can resist corrosion from various media. ③ Austenitic-ferritic duplex stainless steel. Combines the advantages of both austenitic and ferritic stainless steels and has superplasticity. ④ Martensitic stainless steel. High strength, but poor plasticity and weldability. 
Model 301—Good ductility, used for forming products. It can also be rapidly hardened through machining. Good weldability. Wear resistance and fatigue strength are superior to 304 stainless steel. 
Model 302—Corrosion resistance is the same as 304, but due to a relatively higher carbon content, it has better strength. 
Model 303—Made easier to machine than 304 by adding small amounts of sulfur and phosphorus. 
Model 304—General model; also known as 18/8 stainless steel. GB grade is 0Cr18Ni9. 
Model 309—Has better temperature resistance than 304. 
Model 316—The second most widely used steel type after 304, mainly used in the food industry and surgical instruments, with the addition of molybdenum to give it a special corrosion-resistant structure. Due to its better resistance to chloride corrosion compared to 304, it is also used as "marine steel." SS316 is commonly used in nuclear fuel recycling devices. 18/10 grade stainless steel usually also meets this application level.[1] 
Model 321—Similar to 304 in other properties, but with the addition of titanium to reduce the risk of corrosion in the material's welds. 
400 series—Ferritic and martensitic stainless steel. 
Model 408—Good heat resistance, weak corrosion resistance, 11% Cr, 8% Ni. 
Model 409—The cheapest model (UK and US), usually used for automotive exhaust pipes, belongs to ferritic stainless steel (chromium steel). 
Model 410—Martensitic (high-strength chromium steel), good wear resistance, but poor corrosion resistance. 
Model 416—Improved processing performance of the material by adding sulfur. 
Model 420—"Tool grade" martensitic steel, similar to the earliest stainless steel such as high-chromium Brinell steel. Also used for surgical instruments, can be made very shiny. 
Model 430—Ferritic stainless steel, for decorative use, such as for automotive ornaments. Good formability, but poor temperature resistance and corrosion resistance. 
Model 440—High-strength tool steel, with slightly higher carbon content, can achieve high yield strength and hardness of up to 58HRC after appropriate heat treatment, ranking among the hardest stainless steels. The most common application example is "razor blades." There are three common models: 440A, 440B, 440C, and also 440F (easy machining type). 
500 series—Heat-resistant chromium alloy steel. 
600 series—Martensitic precipitation hardening stainless steel. 
Model 630—The most commonly used precipitation hardening stainless steel model, also called 17-4; 17% Cr, 4% Ni.

1. Overview

    The headquarters centrally manages internet video surveillance solutions, based on IP architecture, targeting organizations with headquarters and branches, with user permission management and level concepts, transmitting images over the internet. The headquarters has a dedicated line (fixed IP) connecting to the Internet, while branches have non-dedicated access to the Internet. Multiple users at the headquarters can simultaneously view any camera point, while branch users can only view the camera points of their own branch. This is a commercial application in the industry. By installing network cameras at branches, it connects dispersed, independent video collection points, meeting the needs for real-time video surveillance by multiple people at the center, achieving unified monitoring, unified storage, unified management, and unified scheduling across regions. It is suitable for video surveillance systems in enterprises and groups with branches. It provides a new, intuitive tool for decision-makers in various industries to expand their visual and auditory range, becoming an effective means of supervision and management resources across various sectors.
2. System Features: (Addressing Concerns)
    Rapidly build a unified monitoring system for dispersed camera points: This system can quickly establish a unified real-time monitoring system at headquarters for camera points that are cross-regional, dispersed, and far from cities.
    Real-time monitoring system for multiple users at headquarters: This system can solve the bandwidth bottleneck of Internet transmission, ensuring that when a certain camera point is in focus, multiple users can browse simultaneously without bandwidth bottlenecks.
    Monitoring system that saves network transmission resources: Compared to similar products, this monitoring system's front-end storage and client-demand streaming are optimized. Under the on-demand streaming mechanism, there is no unnecessary video stream transmission between components such as network cameras, platform servers, and clients in the system, which can control the total incoming network bandwidth for receiving real-time streams and can prioritize streaming based on user priority, greatly saving communication bandwidth.
    A powerful and unified WEB client: The MS-1000M integrated WEB server provides a unified web access interface, establishing a B/S architecture with user PCs. Through the web management interface provided by the MS-1000M, users can easily achieve system business configuration, user management, device management, audio and video live preview, live switching, historical image on-demand playback, PTZ control, alarm linkage, web client snapshot and recording, and recording download on any terminal with a web browser.
3. Networking Applications:
    The system mainly consists of front-end network cameras, a central monitoring platform, and monitoring clients. The central monitoring platform is a single MS-1000M integrated monitoring platform server, with the headquarters monitoring center adopting a C/S architecture unified client for 7×24 hours monitoring. Management users adopt a B/S architecture, monitoring through the office PC's IE according to functional requirements. The front-end camera stores motion detection, and uploads to the MS-1000M central recording backup through emergency buttons, fixed times, and motion detection. The headquarters central monitoring platform MS-1000M uses a fixed IP address for wired/fiber broadband access to the Internet, while branch cameras use ADSL or broadband access to the Internet. The front-end D1 storage allows remote access by headquarters, branch control centers, and WEB users, with real-time CIF@25F monitoring and two-way intercom available at any time. A single MS-1000M can manage up to 1000 front-end encoding devices and 6000 client users (decoders/MS/WEB), and can simultaneously receive up to 100 channels of CIF@25F or 50 channels of D1@25F real-time video streams, multicast to multiple users at the center. The system supports access control, with high-privilege users given priority in selecting video streams. The MS-1000M supports tree cascading and horizontal stacking network expansion, with a maximum expansion to 60 units. The system can flexibly expand storage capacity, recording channels, real-time video stream forwarding channels, front-end encoder access numbers, and client user access numbers.
3.1. Application System Architecture:
    The front-end subsystem CIF single stream is multicast to clients after reaching the MS-1000M, satisfying the requirement for multiple users to browse simultaneously when a certain camera point is in focus, without bandwidth bottlenecks. The front-end subsystem D1 records, allowing remote access by clients, with uploads to the MS-1000M center during emergencies, fixed times, and motion detection for mobile monitoring. The central client and mobile sub-control center can simultaneously monitor multiple moving front-end subsystems in real-time video during movement, with two-way voice command for the movement routes of the front-end subsystems. The MS-1000M can save communication bandwidth by adjusting the flow according to MS requests, and it can set the number of simultaneous upload streams, controlling the overall bandwidth, with high-privilege user client requests given priority in bandwidth usage.
4. Main Component Functions:
4.1. Main Functions of the Central Platform Subsystem MS-1000M Server:
    The MS-1000M creatively integrates all the functions required for the monitoring platform into a single All In One device, which is a monitoring platform that combines six major functional modules: integrated WEB service, management and authentication, database, storage, forwarding, and playback. This device uses broadband networks as the communication channel, enabling multiple regions and users to perform real-time monitoring of multiple network camera points, receive/process alarms, record and store, view historical recordings, communicate remotely, and multicast to multiple monitoring points.
4.2. Main Functions of the (aMS) Mobile Monitoring Client:
    Mainly used for real-time video streaming, recording playback, and network camera management, supporting various video browsing, audio listening, two-way intercom, PTZ control, video retrieval and playback, front-end recording backup, automatic configuration search, remote management, and other services. Additionally, it integrates 3G dialing and front-end 3G channel wake-up functions. It supports various video monitoring alarm sources (video loss, motion detection, switch input, etc.) for alarm linkage, and supports various linkage actions (image pop-up, image storage, switch output, PTZ preset position), with alarm sources and linkage actions being flexibly configurable; supports arming/disarming by time period, and manual arming/disarming.
4.3. Main Functions of the (IPC) Network Camera:
    Converts the analog signals from the connected microphone into digital signals, encodes and compresses real-time audio and video signals, stores them, and packages them into IP data packets for transmission over the IP network to a specified destination (multicast mode). The network camera can be configured with a TF card or mobile hard drive, capable of independent operation without relying on other components, plug-and-play, supporting front-end storage (audio and video recording), and motion detection recording to address customer concerns about images while saving storage.