SWJ-73 Deep-Water Thermometer Product Introduction The SWJ-73 is a hydrological and marine testing instrument designed for measuring water temperature at any depth up to 40 meters in rivers, lakes, reservoirs, and runoff test stations. Its measurement range is between -2°C and +40°C. It can also be used for sampling water quality pollution in rivers, lakes, and reservoir areas. SWJ-73 Deep-Water Thermometer Technical Parameters - Total instrument length: 374 mm - Outer diameter of water container: 98 mm - Water container capacity: Approximately 0.5 L - Resistance disk diameter: 150 mm - Instrument error: ±0.2°C