Inspecting and sorting electricity meters

A method was sought for the automatic checking of electricity meters for the presence of critical components and subsequent reworking of non-conforming products

When developers at Ampy Automation Digilog needed a method of determining the presence of critical components on several models of its electricity meters, they considered the use of a vision system to help solve the problem.

After considering various methods, it was felt that a single Checker vision system from Image Industries would prove suitable, and a version was duly purchased.

However, once it had been seen that the unit could inspect up to 20 features on the meters, the project was expanded. It was then decided to include further inspection tasks to confirm the presence and colour of the push buttons used to operate the meter, and the sorting of products. Additionally, one of the models has a silver-coloured washer that could also be inspected by the Checker.

Up to three different models of meter can be produced on the production line at any time, and there is one test conveyor down which the three types can travel in any order. It was therefore logical to use three Checker systems to carry out an inspect-and-sort function so that each meter is directed to the correct calibration station or, alternatively, rejected if it fails the automatic inspection operation.

As each meter passes the first unit, it is inspected for the characteristics that have been programmed for the first type of meter. If the meter passes the inspection, it is diverted to the first calibration station. Failure results in the meter continuing to the next station.

Again, if the meter passes the second inspection, it is diverted to the calibration station for the second type of meter, or if it fails continues to the third station. Again the inspection is repeated, only this time if it fails the meter is diverted to the faulty goods bay, not having been recognised as any of the three models.

A single PLC is used to control the three checkers and the associated conveyors and diversion mechanisms.

Image Industries Tel: 01372 726150