Which of the following is NOT a characteristic of Thermal Mass Flow Meters?

Thermal mass flow meters are specifically designed to measure the mass flow rate of gases or liquids by exploiting their thermal properties. While they do function as accurate flow measuring devices, they are indeed affected by temperature changes. This characteristic primarily arises because the calibration and measurement principles of thermal mass flow meters rely on the heat transfer characteristics of the fluid in question, which can vary with temperature.

The other attributes of thermal mass flow meters contribute to their effectiveness and functionality. For instance, they do measure mass flow rate directly, and their operation is based on the fluid's specific heat, which influences the heat transfer capability. Additionally, they are designed to operate without moving parts, which enhances their reliability and reduces maintenance requirements.

In summary, the assertion that thermal mass flow meters are unaffected by temperature changes is incorrect, making it the choice that does not align with the recognized characteristics of these devices.