An equivalent circuit
  As an electrical element, is composed of a selected crystal wafer, together with the conductive electrode and the protection cover and the inner frame forming means consisting of an electric field in the quartz.
  Crystal resonator equivalent circuit diagram shown in Figure 1.
 

The dynamic parameters of the equivalent circuit L1, C1, R1, and the capacitor C0 and the composition. There are links between these parameters, other parameters may cause the change of a parameter change. And-cut values ​​of these parameters of the equivalent circuit with a crystal, a vibration mode, the operating frequency of the specific design and implementation of the manufacturer a great relationship.
The following two equations are widely used in engineering approximation:
Angular frequency ω = 1 / (L1C1) 1/2
Quality factor Q = ωL1 / R1
Which is equivalent to moving the inductor L1, unit mH
C1 is the equivalent capacitance, also called dynamic capacitance per unit fF
R1 is the equivalent resistance, usually called resonance resistance, unit Ω

     Figure 2, Figure 3, Figure 4 shows the various frequency ranges and a variety of endo-parameterized L1, C1, R1 range.
   Under normal circumstances, the same resonance resistance of quartz resonators of the same production batch of product specifications may have three: the difference between 1. For a given frequency, the smaller the size of crystal cell used, the average value of R1 and L1 may be higher.