Identifying Probable Errors

During the auto-diagnosis of a reconciliation run, Sigmafine collects evidence about each measurement where Test1 produces an absolute value greater than 1.0, and each balance where Test3 produces an absolute value greater than 1.0. Consider the following examples.

EXAMPLE: A

In Example A, Sigmafine determines that meter ME1 is the likely cause of a balance error, and the severity of the probable error is the following.

EXAMPLE: B

In Example B Sigmafine determines that node B does not produce a gross balance error, and that the likely error is produced by node A because of an unrecognized flow. The severity of the probable error is the following.

Severity = (all Test1 > 1.0 absolute values for contributing measurements).

EXAMPLE: C

In Example C, all measurements with Test1 values greater than 1.0 are boundary streams and are connected to a node that has a probable balance error. Sigmafine identifies the boundary measurement with the highest Test1 value as the probable source of the error.

The basis for diagnostic decision is as follows.

• The instrument has the greatest calculated severity, causing balance errors at both ends (as in Example A in the section Identifying Probable Errors).
• The instrument is measuring a boundary stream, causing a balance error (as in Example C).

When the highest severity error is a balance error with no discernible cause (as in Example B,) Sigmafine does not remove any instrument from service.