What tool is used to perform a propylene glycol level test?

The refractometer is the appropriate tool used to perform a propylene glycol level test because it measures the concentration of propylene glycol in a solution based on the refractive index. This device provides precise readings that are crucial for determining the correct concentration of glycol, which is important for various applications such as assessing antifreeze mixtures or coolant systems.

Using a refractometer allows for accurate evaluation of the fluid's properties, ensuring safety and efficiency in systems that use propylene glycol. A hydrometer could measure density but isn't specific to the glycol concentration directly. A thermometer simply measures temperature and does not provide information about the fluid's composition. A pressure gauge measures pressure within systems but does not assess material concentration or content. Therefore, a refractometer is distinctly suited for analyzing propylene glycol levels effectively.