User Manual
17
Figure 3.7 – Series and Parallel Models
The impedance for the series model is:
The impedance for the parallel model is:
These circuit models are mathematically equivalent. The LCR meter measures
an impedance, which gives two independent numbers, the magnitude (|Z|)
and phase (θ) of the impedance. These are changed into rectangular
components R and X, giving the real and imaginary part of the impedance.
These rectangular components can then be transformed into either a series
or parallel circuit of a pure resistance and pure reactance. These transformed
circuits have exactly the same impedance as the measured value, only at the
measured frequency.
Choosing a Test Frequency
Test frequency can greatly affect the results of measurement reading,
especially when measuring inductors and capacitors. This section provides
some recommendations and suggestions to consider.
Capacitance
When measuring capacitance selecting, the right frequency is important in
obtaining the most accurate measurement results. Generally, a 1 kHz and
Series model
Parallel model
R
S
X
S
X
P
R
P