Selecting Circuit Mode Of Inductance - Keysight E4980A User Manual

Measurement Procedure and Examples
Parallel/Series Circuit Mode

Selecting Circuit Mode of Inductance

The following description gives some practical guidelines for selecting the
inductance measurement circuit mode.
Large Inductance (modeled by (a) in
The reactance at a given frequency is relatively large (compared with that of a small
inductance), so the parallel resistance becomes more significant than the series
resistance. Therefore, a measurement in the parallel equivalent circuit mode (Lp-D,
Lp-Q, or Lp-G) is more suitable.
Small Inductance (modeled by (b) in
Conversely, for low values of inductance the reactance becomes relatively small
(compared with that of a large inductance), so the series resistance component is more
significant. Therefore, the series equivalent circuit mode (Ls-D or Ls-Q) is more
suitable.
Figure 7-5 Inductance circuit mode selection
The following rule of thumb can be used for selecting the circuit mode
according to the impedance of the inductor.
Below approx. 10 
Above approx. 10 k
Between above values
For example, to measure a 1 mH inductor at 1 kHz (impedance will be approx.
6.3 ), the Ls-D or Ls-Q function is suitable.
192
Figure 7-5)
Figure 7-5)
Use series circuit mode
Use parallel circuit mode
Follow the manufacturer's recommendation
Keysight E4980A/AL Precision LCR Meter