Placing a monitoring device in an area where people may work is an example of:

Area monitoring refers to the process of placing monitoring devices in specific locations to assess the environmental conditions of those areas, especially in relation to hazardous substances. This type of monitoring is crucial for ensuring safety in workplaces where exposure to hazardous materials may occur. By installing monitoring devices in areas where people may work, you can continuously observe and evaluate environmental hazards that might affect multiple individuals rather than just one person, which is the focus of personal monitoring.

The primary goal of area monitoring is to provide a broader view of potential exposures and to ensure that any hazardous conditions are detected promptly before they can affect workers' health. This proactive approach is essential for maintaining a safe working environment, particularly in industries dealing with hazardous waste or substances.

The other options focus on different aspects of monitoring. Personal monitoring would involve measuring the exposure of individual workers using personal sampling devices, while real-time monitoring refers specifically to the immediate reporting of data as conditions change. Sample analysis typically involves examining collected samples in a laboratory setting, rather than continuously monitoring an environment. Thus, the concept of area monitoring aligns with the act of placing devices in locations where people may frequently work, giving it the designation you've chosen.