The device exploits a composite signal with two frequencies to measure the resistance and capacitance of the system and then compares the measured values with its lookup table to diagnose the position of the file. As a result of modern electronic digital circuits, the manufacturer claims that this device has more consistent readings than its predecessors (Serota et al. 2004). Nevertheless, the fundamental principle of all the ERCLMDs is the same, i.e. an electrical model is assumed and the characteristics of that model are measured to diagnose the clinical properties. Based on clinical observations, Vera & Gutierrez (2004) reported that when using the ElementsTM Diagnostic Unit the file should be withdrawnto the 0.5 mm mark instead of the 0.0 mm mark to achieve the accurate identification of the apical
constriction that they assumed should be 0.5 mm short
of the external (major) foramen. Therefore, taking the
file to the 0.0 mark on the display and then withdrawing
it 0.5 mm appears to be the most accurate way to
use this device. In an attempt to achieve better results
Vera & Gutierrez (2004) also recommended the access
cavity should be dried before introducing the file into
the canal.