Which device is an example of a secondary air sampling calibration device?

The rotameter is a device that is commonly used as a secondary air sampling calibration device because it measures the flow rate of gases and liquids in a tube. It operates on the principle of variable area flow measurement, where the flow rate is indicated by the position of a float within a calibrated tube. This capability makes it particularly useful for ensuring that air sampling equipment operates at the correct flow rate, which is essential for the accuracy and reliability of sampling results in occupational hygiene monitoring.

In the context of air sampling, maintaining a consistent flow rate is crucial because it influences the amount of airborne contaminants collected, thereby impacting analysis accuracy. The rotameter allows for real-time monitoring of flow rates, assisting in the calibration of other sampling devices by ensuring they are set to the correct operational parameters. This is a key function in occupational hygiene, where precise measurements of exposure levels are necessary to assess risks to worker health.

The other devices listed serve different primary functions and do not play the same role in calibrating air sampling equipment. For instance, a Gilibrator is primarily a device for calibrating air sampling pumps but does not operate as a flow measurement indicator. A thermometer measures temperature rather than flow rates, and a manometer measures pressure differences rather than flow. Thus,