Solvability Examples

The following are a few sample configurations and their corresponding solvability results.

Solvability Example A: Redundant Measurements

When all the flows around a balance point are measured, you can check any one against the others.

The following figure shows an example of this: A processing unit with one flow in and two flows out, all with meters attached.

EXAMPLE A

Solvability Example B: Solvable Measurements

When all flows except for one are measured around a balance point, then the redundancy collapses. However, you can calculate the last flow from the difference of the measured flows.

The following figure shows an example of this: A processing unit with one measured flow in and two flows out. One flow is measured and one is not measured.

EXAMPLE B

Solvability Example C: Non-Solvable measurements

When multiple flows around a balance point are unmeasured, the solvability collapses farther and non-solvable flows appear.

The following figure shows an example of this: A processing unit with one measured flow in and two unmeasured flows out.

EXAMPLE C

Solvability Example D: Non-Solvable Internal Measurements, Solvable Boundaries

A Model that has unsolvable areas in it does not necessarily become completely unsolvable. Often it is possible to examine the boundaries of an area, especially places of custody transfer, and find enough measurements for a solvable outcome.

The following figure shows an example of this: One processing unit connected to a second one. The flows in the middle of the Model are not measured, but the flows into the first unit and out of the second unit are measured.

In this example, the boundaries of the Model are all measured, and therefore there is redundancy at the boundary.

EXAMPLE D