What is a Lithometer?

A lithometer is an instrument used to measure the concentration of dry particles suspended in the atmosphere, which is consistent with the definition provided in the chosen option. These particles may include dust, smoke, pollen, or other particulates that can impact air quality and visibility, making the understanding and measurement of lithometers important in meteorological observations and studies.

The context of the other choices clarifies why they do not fit the definition of a lithometer. The first option describes a temperature measuring device, which is unrelated to the measurement of particulate matter. The third option discusses cloud height, a different meteorological measurement altogether that typically relies on other instruments such as ceilometers. Lastly, the option regarding wind speed pertains to anemometers, which measure wind velocity rather than particulate concentration. Each of these options aligns with different aspects of meteorological measurement, further reinforcing the unique role that a lithometer plays in atmospheric analysis.