# The Use of Augmented Reality for the Management of Equipment Ageing with a Virtual Sensor
## 4 Results
### Discussion  
A comparison with other solutions that use AR in the inspection sector has been made. The virtual sensor allows the equipment integrity to be controlled, while other widespread systems support checking the correct connection of fittings and performing routine maintenance by using information superimposed on the equipment. The developed sensor shows the information that is useful for quantifying ageing metrics and permits the integration of new information acquired on-field. In this way, new information can be annotated without using a paper notebook, and such information is included in the application, which appropriately organises the input file for the models. then, it is also possible to process input data in order to elaborate ageing indexes and generate iso-corrosion maps. The advantage is having a lot of information, in tabular and visual form, through a minimalist and intuitive interface. This availability would not otherwise be possible on-field because this information is generally archived on paper.  
In summary, the comparison with AR solutions reported in the literature shows similarities with the use of AR in the virtual sensor. These are related to the opportunity to overcome the limit of using paper-based annotations during inspections and to help operators in performing tasks and operations by the addition of information to the real work environment. This is possible without adding new risks for the worker. As regards the monitoring and assessment of equipment ageing, the virtual sensor appears to use AR in an innovative way within the inspection sector.  
Based on what has been discussed above, the virtual sensor appears innovative as there are no AR-based tools for the monitoring and assessment of equipment ageing. This allows the virtual sensor to be positioned within the broader context of existing systems but with this specific peculiarity. The virtual sensor helps in running numerical models for ageing assessment, the application of some of which is useful to the establishment operator in order to comply with the Seveso legislation. The evaluation of the adequacy of ageing management is a crucial matter, especially when the equipment is close to the end of its lifetime. Therefore, having tools that help in the acquisition and management of input data to the models represents a valid support for the operator. Unfortunately, the use of these tools requires experimental validation tests in the laboratory to ensure that their development does not introduce new risks, such as those associated with human-machine interaction. The test results of the virtual sensor demonstrated the effectiveness of the support provided by the system to the inspector. This effectiveness was quantified through interviews with the users. The questions led to the following evidence: (1) the system allows the operator to be able to manage a lot of information and to combine visual deductions with forecasts obtained from the models, in order to understand the real expected evolution of the phenomenon, also on the basis of how it is managed. (2) the developed interface allows the information to be managed without creating confusion for the user.