DX3 - Tolerance Indicator

The DX3 - Tolerance Indicator indicates the effective tolerance for the current redundantly measured flows. Typically, this is half of the tolerance used for the Test1 in Sigmafine. This index is expressed as a percentage. It is a basic information index to give calibration for other DX indexes. You can expect the Imbalance Indicator (DX1) and the Reconciled Correction Indicator (DX2) to be less than the Tolerance Indicator (DX3) if you have a Model with good data quality. This is because the typical tolerance is two standard deviations (a 95% confidence level). If this is not the case, it may indicate that the tolerances are incorrectly assigned.

DX3 is calculated by the following equation:

DX3 = RMS (Tolerances) / RMS (Redundant Flows)

Where:

I = ith flow/transfer/inventory that is in service.

N = total number of redundantly measured flows/transfers/inventories.

QT\= value of the mass tolerance of the measurement that is redundant.

QR\= value of the mass or a measurement that is redundant.