The E. coli online automatic monitor, with its high efficiency and accuracy, has become a reliable assistant in water quality monitoring. It can quickly detect harmful microorganisms such as total coliforms and Escherichia coli, and is widely used in various fields including drinking water, surface water, wastewater, and bathing water. The VLAN/Ecoli-900 analyzer, launched by Weilan Environment VLANINC, has become a market leader thanks to its professional services and high-quality products. The VLAN/Ecoli-900 not only adopts the standard enzyme substrate detection method, supports multiple detection methods, and enables online monitoring of various bacterial groups, but also features an intelligent and user-friendly operation interface with broad application areas. It is capable of handling tasks ranging from water source monitoring to environmental pollution source monitoring with ease. It operates reliably in various extreme environments, ensuring high consistency in detection results, providing a reliable basis for long-term water quality monitoring and management. Additionally, it dynamically displays reaction curves, automatically generates reports, and immediately alerts to water pollution incidents upon detecting abnormalities, offering critical support for relevant authorities to take timely action. In the context of drinking water, it utilizes changes in light signals after the reaction between enzymes and bacterial cultures to monitor E. coli levels in real-time online, ensuring the safety of residents' drinking water. In the wastewater sector, it monitors E. coli in sewage in real-time, preventing pollution discharge and helping enterprises identify issues promptly to reduce risks. For surface water, it provides early warnings of water pollution incidents, protecting the ecological environment. When selecting an E. coli monitor, accuracy is the primary consideration. The VLAN/Ecoli-900 has an error rate of less than 35%, accurately reflecting the E. coli content in water. Secondly, ease of operation and low maintenance costs are also important. The VLAN/Ecoli-900 features an oversized color screen, hierarchical password protection, easy-to-clean components, and automatic disinfection and cleaning functions, making operation and maintenance more convenient. Furthermore, the flexibility and applicability of the monitor cannot be overlooked. The VLAN/Ecoli-900 can adapt to different sample types, detect multiple parameters, and perform on-site calibration based on water sample characteristics, meeting various needs.