What are the two types of XRF analyzers mentioned?

The correct answer identifies the two types of XRF analyzers as Direct Reader and Spectrum Analyzer. Understanding these two categories is essential for recognizing how XRF technology functions in assessing lead and other heavy metals in various materials.

A Direct Reader XRF analyzer provides immediate results directly on the device's display, making it highly efficient for field testing. This type facilitates quick decision-making at the location, which is particularly useful in lead risk assessments, where timely results can significantly impact safety and remediation actions.

On the other hand, a Spectrum Analyzer operates by collecting data that is then analyzed in detail, often providing more comprehensive results regarding the elemental composition of a sample. This analysis can be vital in laboratory settings where precision is critical and in-depth data analysis is required to understand the presence and concentration of specific elements.

The other choices do not accurately encapsulate the specific functions or types of XRF analyzers. While Old and New Models might refer to advancements in technology, they don't highlight the operational distinctions within the analyzers. Field and Laboratory Models could seem relevant, but they do not reflect the actual mechanics of how the analyzers classify data. Lastly, Portable and Stationary Types focus on the mobility of the devices, rather than describing their analytical capabilities and functions. Thus,