The Cornell Electron Storage Ring (CESR) is a 768 meter former electron-positron collider which is hidden beneath the school's Alumni Field and a parking area. Throughout the 1990's the CESR was the world's highest luminosity electron-positron collider.

Inferred measurement is when characteristics of the flowing media are known or measured, and then used in an equation to calculate the mass flow rate of the media. A thermal mass flow meter is an example of an instrument which provides an inferred measurement. Information about the media, such as heat capacity, must be known and this is used in an equation to calculate the mass flow rate. In addition to the known factors in the equation there is also the variable factor. In one variation of the technology a differential temperature between measuring points on the sensor is used where the higher the flow the larger the differential temperature between sensor measurement points.

An inferred mass flow measurement instrument is a good choice when the characteristics of the flowing media are known and will be constant so that the calculated value, and thus the mass flow rate, only changes as the differential temperature (in our example) changes. When characteristics of the flowing media are not constant, such as in a changing mixture, then significant additional error can be introduced into the measurement.

A simple as it sounds; direct measurement is when the instrument measures the mass flow rate directly, without the need for knowing additional characteristics of the flowing media. The sole example of a direct mass flow measuring device is a Coriolis flow meter. Gas or liquid, pure or mixture it does not matter as the Coriolis meter is directly measuring the mass of the flowing media.

A direct mass flow measurement device is a good choice to provide an accurate flow rate when there could be variations in flow requirements, flowing media, and other process conditions.