What instrument measures the volume of gas delivered?

The instrument that measures the volume of gas delivered is a meter. Specifically, gas meters are designed to accurately quantify the amount of gas flowing through a system over time. They work by capturing the volume of gas as it passes through and display this measurement, which can be crucial for various applications, including billing for gas utilities, monitoring gas consumption, and ensuring systems are operating efficiently.

Pressure gauges assess the pressure of gases or liquids and are important for equipment safety and function, but they do not provide volume readings. Calorimeters are used to measure the heat of chemical reactions or physical changes, making them unsuitable for measuring gas volume. Thermometers simply measure temperature and provide no information about gas volume. Thus, for indicating the volume of gas delivered, a meter is the appropriate instrument.