The GS1 system gives each electricity meter a unique identifier. In addition, this identifier can be rapidly and reliably read from a bar code.
Unique meter identifiers using the GS1 system
Meters are identified using a GIAI (Global Individual Asset Identifier) which is 30 digits long. In Sweden some network companies prefer to use only 16 digit identifiers.
The meter identifier consists of a GS1 company prefix, a sequence number, and a check digit. A GIAI does not normally have a check digit, but a check digit is used for the 16 digit meter identifiers which makes input and bar code reading more reliable. Each company prefix allows for 1 million unique 16 digit identifiers.
Structure of a meter identifier
Meter identifier (Swedish example): 7 3 X X X X X X X A A A A A A K
73X...X = GS1 company prefix
A...A = sequence number
K = check digit
Allocating meter identifiers
There are three alternative ways of allocating electricity meter identifiers. Remember that the network company and the meter supplier must agree in advance who is responsible for meter identification.
Irrespective of who numbers and marks the meters, it is essential to keep track of which numbers have been used. Two meters must never be given the same number.
- The network company subscribes to a company prefix and insures that the meters are numbered and marked with a GS1 individual asset identifier. Depending on what has been agreed with the meter supplier, this numbering can be done by the supplier or the network company itself.
- The meter supplier subscribes to a company prefix and numbers the meters. The prefix is used only to number meters to a single network company. When all numbered and marked meters have been delivered the supplier transfers the number series to the network company.
- The meter supplier subscribes to a company prefix and numbers the meters. The prefix is used to number meters for delivery to different network companies. When delivery is complete the supplier retains and is responsible for the company prefix.
Within the GS1 system the same company prefix can be used to create new unique identifiers for both installations and meters.
Rules in the event of sale or transfer
Meters which have been numbered with a GIAI must never be renumbered since each meter must be traceable for a long time in the event of a dispute on meter readings or accuracy. If a network company sells part of its network, the buyer must ensure that the associated meters retain their identity and the responsibility for the company prefix used to number one is unchanged. If a network company ceases to trade and is completely transferred to another company then the company prefix must be transferred to the new owner if the meters have been identified using alternatives 1 or 2 above.
Marking a meter with a barcode
Electricity meters are marked using bar code symbology GS1-128 in the same way as installations. For meter identifiers the application identifier (AI) 8004 is used. Application identifiers are used by the bar code reader to identify the data element type and to correctly process the information in a business system. Both the AI and the meter identifier are included in the bar code and the digits are printed beneath the bar code with the AI in parentheses.
The picture shows an example of how the bar code is placed on the meter. The digits under the bar code: (8004) 5055142812345674 (allocated by a British company for the Swedish market) .
