What is the main advantage of using positive displacement flow meters?

The main advantage of using positive displacement flow meters is that they provide high accuracy even with varying fluid densities. This is due to the operating principle of positive displacement flow meters, which measures the volumetric flow rate of a liquid by trapping a fixed volume of fluid in a chamber and then counting the number of these volumes that pass through the meter within a specific time frame.

This measurement method is highly reliable because it doesn't rely on the fluid's density or viscosity; instead, it focuses on the physical volume of fluid moving through the meter. As a result, positive displacement meters maintain their accuracy across a wide range of fluid conditions, which makes them particularly valuable in applications where fluid density might change, such as in oil and gas industries or chemical processing.

In contrast, the other options present different advantages that do not specifically relate to the inherent measurement accuracy of positive displacement flow meters, such as manufacturing costs, installation simplicity, or temperature measurement capabilities.