YSI is the maker of environmental, laboratory, and municipal monitoring instruments, sensors, software, systems, and data collection platforms for water quality monitoring and testing, water velocity data, and more. Measure with confidence! Analytics for decision. Our multiparameter instruments, aquaculture monitoring systems, handheld sampling instruments, and complete line of SonTek (velocity) products can be incorporated into any of your monitoring or sampling applications. Our instruments have the ability to be used in the field or the lab, and can even be used in unattended settings. We build long-lasting relationships with our customers through our dedicated customer service, including technical applications and service support by Read more