Wireless Sensing Based on RFID and Capacitive Technologies for Safety in Marble Industry Process Control

Table 2

Main performance of the RFID systems (passive tags) for marble slab detection.

RFID System	LF 125 kHz	HF 13.56 MHz	UHF 868 MHz
Radiated power	100 mW	<50 mW	<500 mW
Max. stone detection distance	15 cm	<8 cm	<40 cm
Best tag placement	Side surface of the marble slab		Embedded in the conveyer belt or under it
With water	Works		Does not work
With dust/dirt/stone residuals	Works