Question 94General Subjects - 1st Asst/Chief

The correct answer is A) thermometer. A salinometer is used to measure the salinity of water, and a thermometer is the instrument that is always used in conjunction with a salinometer. This is because salinity measurements are affected by temperature, so the temperature of the water sample must be measured alongside the salinity reading to ensure an accurate salinity measurement. The other options are incorrect because they do not directly relate to the measurement of salinity. A pyrometer measures temperature, a hygrometer measures humidity, and a hydrometer measures the density of liquids, but none of these are used in conjunction with a salinometer for salinity measurements.