Velleman LCR40 - Manual (Page 9)

Atlas LCR User Guide January 2009 – Rev 4
Page 9
Low Value Capacitors
There is a vast range of low value capacitors available. Types include ceramic,
polyester, polystyrene and mylar dielectric capacitors. Generally, low value
capacitors tend to be unpolarised. Minimum capacitance resolution is about
0.1pF.
Capacitor test frequency:
The Atlas LCR uses a high purity sine wave signal
of 1kHz, 15kHz or 200kHz to analyse these types of capacitors. The
frequency is automatically selected to give the best possible measurement
resolution.
The following table shows the test frequencies used for various capacitance
ranges:
Capacitance Range Test Frequency Used
Between 0pF and 1nF 200kHz
Between 1nF and 15nF 15kHz
Between 15nF and 1µF 1kHz
Above 1µF DC
The capacitance ranges for each test frequency shown in the table above is
approximate. Effects such as leakage, dielectric dissipation and ESR can
influence the frequency that the Atlas LCR selects for your particular
capacitor.
Capacitor results:
Following analysis of the capacitor, the capacitance value
is displayed first. Press the scroll-off button to display the frequency at
which the capacitance was measured.
Capacitance Capacitance Capacitance Capacitance
48.3pF 48.3pF 48.3pF 48.3pF
Test frequency Test frequency Test frequency Test frequency
200kHz 200kHz 200kHz 200kHz