Which tool is used to measure the pH of a substance?

The pH strip or pH meter is specifically designed to measure the acidity or alkalinity of a substance. The pH scale ranges from 0 to 14, with lower values indicating more acidic conditions and higher values indicating more alkaline conditions.

A pH meter provides a digital reading and is often used in various professional settings for precise measurements. It consists of a probe that is sensitive to hydrogen ion concentration, allowing it to give accurate pH values for liquids. pH strips, on the other hand, are coated with pH-sensitive dyes that change color when they come in contact with a solution, providing a quick visual indication of pH levels.

Other tools listed serve different purposes. For instance, a thermometer is used for measuring temperature, a hydrometer measures the specific gravity or density of liquids, and a refractometer measures the extent to which light is bent when it passes through a liquid. These tools do not provide information about the pH level of a substance, making the pH strip or pH meter the correct choice for measuring pH.