What is the function of colorimetric indicator tubes?

• A. To measure temperature changes
• B. To detect specific gases or vapors by color change
• C. To assess humidity levels
• D. To analyze soil composition

Answer: (B)

Colorimetric indicator tubes serve a crucial function in detecting specific gases or vapors by producing a visible color change in response to the presence and concentration of those substances. These tubes contain a reactive chemical that interacts with the target gas, leading to a distinct color shift. This allows users to not only identify the presence of a particular gas but also estimate its concentration, which is vital for ensuring safety and compliance in hazardous environments.

The other options do not align with the primary function of colorimetric tubes. For instance, measuring temperature changes relates to thermal dynamics, which is not accomplished by these tubes. Similarly, humidity assessment involves hygrometers or similar devices rather than colorimetric indicators, while soil composition analysis typically requires different types of testing tools and methods entirely.