OIML E 6 • Guidance on the selection and implementation of performance requirements for utility meters containing additional functionalities

4.2.3 Analysis of the smart meter design

In addition to the evaluation of the correct metrological operation of a (module of a) system itself therefore, an analysis is needed of whether the stored parameters and recordings are secure, and also whether all the possible (available) interfaces/interconnections of the system to the environment (and the manner in which these could serve as an entrance port for undesired influences) are secure.

As a consequence, it is necessary to include of all the available input and/or output ports to the environment, and also the expected behavior of this environment itself.

For this, it is necessary to break the system down into, for example:

  • the several constituent parts of the measuring system;

  • the environment; and

  • the interconnections (input and output ports).

Following this, those parts that are relevant to the measurand or that could influence the measurement result may be defined.

The following distinction in devices based on metrological relevance can be made in the assessment of the measures taken to prevent incorrect measurement results:

Devices with internal recording of data

For devices that are designed to record measurement results, the assessment of the risk of loss or violation of data in the record is to be applied. Besides the measurement data from the measurand this also concerns other possible parameters of importance to the result used for transactions, such as recording the time and time interval measurements.

Devices without internal recording of data

For devices that do not record measurement data but instead transmit it to some data collection point, it should also be assured that the risk of violation of data as a consequence of transport through the data transmission medium is diminished.