Which tool may be necessary for conducting simultaneous radon tests?

Conducting simultaneous radon tests requires the use of radon detection devices because these specialized tools are designed to measure radon gas levels accurately in real-time. In situations where multiple tests are needed at different locations or conditions, these devices can provide consistent and reliable readings, allowing for an analysis of varying radon concentrations in different areas at the same time.

Other tools such as a digital calculator or a humidity measuring device may support the overall testing process, but they do not serve the primary function of measuring radon levels directly. A radiation shield is also not essential for conducting radon tests, as it does not contribute to the capability of detecting radon gas itself. Hence, radon detection devices are indispensable for successfully conducting simultaneous radon tests and obtaining valid data.