Hioki IM7580, Instruction Manual

Page: 316 / 340

A
4
Series Equivalent Circuit Mode and Parallel Equivalent Circuit Mode
Appx. 3 Series Equivalent Circuit Mode and Parallel
Equivalent Circuit Mode
The instrument measures the current flowing to the test sample and the voltage at both ends of
the test sample, and determines Z and
Ω
. Other measurement items such as L, C, and R are
calculated from Z and
Ω
. At this time, the calculation mode is series equivalent circuit mode if the
resistance components for C (or L) are assumed to be in series, and the mode is parallel equivalent
circuit mode if the resistance components for C (or L) are assumed to be in parallel. Therefore, it
is necessary to select the correct equivalent circuit mode to reduce errors because the calculation
formula differs for series equivalent circuit mode and parallel equivalent circuit mode.
Generally, a series equivalent circuit mode will be selected for measurement of a low impedance
device (approximately less than 100
Ω
) of large capacitance capacitor and low inductance. While,
a parallel-equivalent circuit mode will be selected for a high impedance device (approx. more than
10 k
Ω
) of small capacitance capacitor and high inductance. When you are not sure about selection
of circuit mode (ex. an impedance approx. between 100
Ω
and 10 k
Ω
), check with the parts
manufacturer.
C (or L)
C (or L)
Series equivalent circuit Parallel equivalent circuit
Measurement values of both modes can be displayed because measurement value in each
equivalent circuit mode is obtained by calculation. However, please note that the appropriate
equivalent circuit depends on the test sample.