Which of the following is considered a primary standard for measuring lung function?

A bubble meter is a primary standard for measuring lung function primarily because it provides a simple and direct method for determining the volume of air inhaled and exhaled by an individual during respiratory activities. This device can accurately measure lung volumes and is often used in clinical settings to assess pulmonary function, making it an essential tool in respiratory health evaluation.

In contrast, a force plate is primarily used to assess physical forces and movements, not specific to lung function. A dosimeter is an instrument for measuring exposure to hazardous substances, such as chemical agents or radiation, rather than directly measuring lung ventilation or function. A carbon monoxide monitor specifically measures the concentration of carbon monoxide in the environment or in exhaled breath, which is related to carbon monoxide exposure, not overall lung function. Thus, the bubble meter stands out as the most relevant tool for assessing lung health directly.