Tegam 3550 - I Instrument Description

Model 3550 LCR Meter Instruction Manual Instrument Description
1-13
Formulas and Measurement Accuracy
Parameters and Formulas
Generally speaking, the characteristics of circuit components can be evaluated in terms of
impedance (Z).
The 3550 LCR Meter measures the voltage and current components of the circuit in relation to the
alternating signal of the measurement frequency, and uses these values to calculate impedance
(Z) and phase angle (LJ).
Displaying impedance (Z) in a complex notation as below allows us to determine the following
values.
ș
REAL NUMBERS
IMAGINARY NUMBERS
R
jX
Z
Z
V
I
Z =V / I
Z=R+jX
LJ = TAN
-1
X/R
R
2
+X
2
|Z| =
Z: Impedance (ƻ)
LJ: Phase Angle (deg)
R: Resistance (ƻ)
X: Reactance (ƻ)
|Z|: Absolute Value of Impedance (ƻ)
Depending on the properties of the DUT, Admittance (Y), which is the inverse of Impedance (Z),
may be used to calculate parameter values instead. Admittance (Y), like Impedance (Z) can be
represented in complex notation in order to calculate the following values.
ij
REAL NUMBERS
IMAGINARY NUMBERS
G
jB
Y
Y=G+jB
ĭ= TAN
-1
(B*G)
|Y|=
Y: Admittance (S)
G
2
+B
2
G: Conductance (S)
B: Susceptance (S)
|Y|: Absolute value of Admittance (S)