The turbidity sensor, is a ultra-low turbidimetry based on the principle of 90° scattered light, using high parallelism, with automatic light intensity correction laser light source and highly sensitive detector. Its detection performance at low turbidity (<1NTU) is excellent. The turbidity sensor is equipped with automatic optical window cleaning function, which is maintenance-free for a long time for tap water application scenarios. In addition, with the DL-W-S series meter head transmitter and WQS-Server (WQS cloud service), users can realize on-site and remote data viewing.