Tsurumi Seiki (T.S.K) develops and manufactures instruments for observing oceans, inland waters, and the atmosphere. Drawing on decades of experience, the company supports water research from initial consultation and product design through production, operation, and maintenance. It works with customers to understand their requirements, propose suitable specifications, and build equipment designed around the realities of field use. Support also includes user guidance and servicing after deployment.

Its marine observation products include expendable oceanographic systems, profiling floats, benchtop salinometers, research winches, sampling and water-collection equipment, and wave and tide gauges. For inland-water monitoring, the company offers automatic water-quality monitoring systems, while its atmospheric observation range includes GPS radiosonde systems. Tsurumi Seiki also provides solutions and equipment for research vessel operations and scientific surveys. Its project experience includes Antarctic and Greenland glacier observations, deep-sea robotic monitoring, and instrumentation supplied for research ships. Through its products and technical support, the company aims to help researchers collect reliable measurements and turn them into useful insight across diverse field environments.