# Testing of Permeability of RFID Access Control System for the Needs of Security Management
## 3 Methodology  
In our testing, we focused on the capacity limits of the RFID card reader and the effect of the reader placement distance on the card reading capability. The data that were found are not reported by the reader manufacturers. Nevertheless, they are of great importance in the practical use of RFID or NFC readers in practice. Since many errors and shortcomings can occur in manual testing, we used a testing device that helped to eliminate inaccuracies.  
The device for testing RFID access readers and RFID chips in the form of cards can perform a continuous rotary motion and thus simulate the attachment of an RFID card to the reading device at specified time intervals and at a selected distance from the reading device. At the same time, it senses the number of simulated attachments of the RFID chips in the form of cards to the reading device by means of an optical or inductive counter. The frame of the device is made of plastic using a 3D printer. It has an adjustable height, which allows for changing the distance of the reading device. The drifter has a circular form and is mounted on bearings and driven by a DC motor with a gearbox and speed control. The control electronics are mounted directly on the device together with the counter. The device is equipped with an inductive speed counter (counts the number of RFID cards) (Figure 2).  
The results of the reader pilot tests, showing the ability of the Crypton x112 reader to correctly read RFID cards and tags, are shown in the Figure 3.  
There is a noticeable decrease in the ability to read RFID cards and tags as the distance of the reader location increases. A total of 6000 repetitions were performed across the three types of tests. In this case, 15 measurements with 100 repetitions of reading an RFID card or RFID tag.  
Figure 2: Test device (1—base; 2—electric motor; 3—control electronics; 4—drift; 5—RFID or NFC chip in the form of a card or a tag; 6—frame; 7—counter; 8—bearing).  
In the experimental tests, which are covered in the given manuscript, we used the methodology from the pilot tests carried out using the first version of the test device. The principle consisted of the established maximum communication distance and the subsequent determination of three standard distances within the scope of the given communication distance. Subsequently, multiple repetitions were carried out through which we determined the reliability of card reading. These data are very important, especially from the point of view of the need of security managers to know at what distance RFID systems can fully function so that they do not cause downtime when changing workers in a work shift.  
During the pilot tests, we realized that the testing equipment needs to be improved to automate the entire testing process even more and eliminate the influence of the human factor on testing. That is why we added a large sliding scale to the designed device, formed by a metal belt with a magnetic structure, to which any reader of the input control system can be attached; thus, the same distance is ensured during the entire measurement.