The initial metering message received by a client contains non-validated data. This should not be confused with the quality of the data – for even if all power values are labelled as normal (N) this does not yet mean that they are validated. The validity of the data applies to the complete set of values in the schedule. Data is validated by processes and checks carried out by Elia. When message is validated, the values are guaranteed to be correct by Elia.
Power values can be measured, calculated or estimated. Every power value in the message is assigned a quality label which can be one of the following:
- N (Normal) This refers to normal measured values, usually determined by a single properly functioning meter.
- I (Inexact) Power values may be labelled as inexact for a number of reasons. It may be because there was a perceived problem with the meter, or that values were calculated from combined measurements from several meters, one of which was inexact. Elia still has to verify the values and it is possible that these values will be corrected later.
- S (Substitute) If no measurement is available, an estimated value is used.