Improvements in or relating to electricity meters

摘要

A modulised utility meter comprising a basic meter module, which is adapted for fixture in the premises of a consumer, and an 'add-on' module which is adapted to be received by the basic meter module, the modules each including a central processor unit (CPU), which serves to control operation of the module with which it is associated, which CPU includes a store for data appertaining to a quantity of the utility used as measured by meter means in the module of which it forms a part, and a comparator in one module which is arranged to compare the data of respective modules, and to provide an output signal in the absence of predetermined correspondence therebetween.