1) INTRODUCTION
Before starting, first we have to understand some terminologies in electric current.
What is Resistance?
Complete Opposition of Flow of Current in DC Circuit is called resistance
What is Impedance?
Complete opposition of flow of current in AC circuit because of resistance and capacitance called impedance.
Impedance comprises of Resistance and Capacitance of AC Circuit. Change in resistance and capacitance of ac current results in change in impedance
Resistance does not vary depending upon the frequency of DC current.
Impedance depends upon the frequency of AC current. Again change in frequency results in change in impedance.
Frequency can be Low, High, Single frequency, Multiple frequency.
Now the Multiple frequency can be use Simultaneously or Separately.
A) FIRST GENERATION APEX LOCATOR
The first generation of apex locator, also known as resistance apex locator, measure
opposition to the flow of direct current or resistance.
B) SECOND GENERATION APEX LOCATOR
Second generation apex locator, also known as impedance apex locators, measure opposition to the flow of alternating current or impedance.
The second-generation apex locators used single high frequency impedance measurements to measure locations within the canal.
C) THIRD GENERATION APEX LOCATOR
Third generation apex locators were similar to second generation but used simultaneously multiple frequency rather than single frequency impedance.
D) FOURTH GENERATION APEX LOCATOR
This generation apex locators also used multiple frequencies, but only one frequency at a time yielding increased accuracy.
The manufacturers claim that the combination of using only one frequency at a time and basing measurements on the root mean square values of the signals increases the measurement accuracy.
E) FIFTH GENERATION APEX LOCATOR
This generation apex locators were developed in 2003.
They measure the capacitance and resistance of the circuit separately.
These ones do not use the impedance value as a mathematical algorithm only to assess the working length but instead utilize the resistance and capacitance measurements
Before starting, first we have to understand some terminologies in electric current.
What is Resistance?
Complete Opposition of Flow of Current in DC Circuit is called resistance
What is Impedance?
Complete opposition of flow of current in AC circuit because of resistance and capacitance called impedance.
Impedance comprises of Resistance and Capacitance of AC Circuit. Change in resistance and capacitance of ac current results in change in impedance
Resistance does not vary depending upon the frequency of DC current.
Impedance depends upon the frequency of AC current. Again change in frequency results in change in impedance.
Frequency can be Low, High, Single frequency, Multiple frequency.
Now the Multiple frequency can be use Simultaneously or Separately.
A) FIRST GENERATION APEX LOCATOR
 |
| First Generation Apex Locators |
The first generation of apex locator, also known as resistance apex locator, measure
opposition to the flow of direct current or resistance.
B) SECOND GENERATION APEX LOCATOR
Second generation apex locator, also known as impedance apex locators, measure opposition to the flow of alternating current or impedance.
The second-generation apex locators used single high frequency impedance measurements to measure locations within the canal.
C) THIRD GENERATION APEX LOCATOR
Third generation apex locators were similar to second generation but used simultaneously multiple frequency rather than single frequency impedance.
D) FOURTH GENERATION APEX LOCATOR
This generation apex locators also used multiple frequencies, but only one frequency at a time yielding increased accuracy.
The manufacturers claim that the combination of using only one frequency at a time and basing measurements on the root mean square values of the signals increases the measurement accuracy.
E) FIFTH GENERATION APEX LOCATOR
This generation apex locators were developed in 2003.
They measure the capacitance and resistance of the circuit separately.
These ones do not use the impedance value as a mathematical algorithm only to assess the working length but instead utilize the resistance and capacitance measurements