BS ISO 20912:2020 pdf download.Conformance test methods for RFID enabled tyres.
Also, there shall be no ceiling or at least no ceiling closer than those distances defined in 4.2.3.2 and 4.2.3.3 from the top of the tyre.
The ground and the ceiling shall minimize electromagnetic reflections during the measurement in order to ensure the accuracy of the test result.
— No atmospheric event (such as snow and rain) shall take place at the testing area during the measurement.
— No environmental change shall occur during the measurement.
— There shall be at least a free space of 2-m radius (excluding testing equipment and device under test) around the tyre on the horizontal plane.
— Personnel should be prohibited to be in the proximity of a 2-rn radius around the test setup.
— The operator shall remain behind the reader (and not between the reader and the tag).
— In general, the permeability and permittivity of supporting equipment like tyre stand and others should be low to not influence test results.
To prevent any interference, it is recommended to set up a site survey in order to detect any use of radio frequency within the RFID frequency band. This can be done with a spectrum analyser and a UHF antenna to ensure that the radio frequency transmission levels are at least 10 dB smaller than the backscattering signal from the RFID enabled tyre.
4.2.3 Testing layout
4.2.3.1 General
Two testing layouts are defined. It is up to the tyre manufacturer to choose one or the other, depending of the RFID tag implementation/position.
4.2.3.2 Testing layout for the RFID In/on the tyre sidewall The layout is depicted in Figure 1.
The minimum distance, h1, between the tag position and the ground shall be at least at 1,5 m or 5 times of the minimum reading distance defined in ISO 20909. whichever is the lowest.
The tyre shall be put directly on the ground or on a stand in the testing site, unmounted from the rim.
The minimum distance, h2, between the tag position and the ceiling shall be at least 1,5 m or 5 times of the minimum reading distance defined in ISO 20909. whichever is the lowest.
The area where the RFID tag is located shall be horizontally aligned with the reader’s antenna as per the following description. To locate the RFID tag, the operator monitors the RSSI or RPS. Once the largest RSSI (or RPS) is obtained, the alignment between the tyre and the reader’s antenna is adequate.
NOTE The largest RSSI can be unreliable for short distance between tag and reader. Instead a local maximum or minimum of the RSSI can indicate an adequate alignment.
The tyre sidewall surface containing the RFID tag shall be directed towards the reader’s antenna.BS ISO 20912 pdf download.