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© Copyright Siborg Systems Inc.
When the measured component is connected to the test leads,
the screen displays information depending on the component
and the selected settings in the R-L-C-D mode menu.
Inductance
Capacitance
Resistance
Diode
In automatic mode, measurement of capacitance larger than 0.9
μ
F by default is made at 120 Hz, while ESR is measured at 100
kHz. In this case the display looks
as follows. The frequency is not
shown on the screen, but two
additional numbers are displayed indicating the capacitor
parameters described below.
The main criterion for rejection of electrolytic capacitors is the
value of ESR that varies amongst the types of capacitors and
manufacturers. Two ESR tables have been compiled with typical
ESR values for various capacitances/voltages, one for regular
electrolytic capacitors and the other for Low ESR capacitors
(presented below in Supplement A and B). These are indicative
values and should only be used for a rough estimation of the
capacitor performance. In this case besides the measured ESR
value, two additional numbers are displayed in the right top
portion of the screen. The first number indicates quality of the
capacitor measured as a ln(Rs/Rt) where Rs is the measured ESR
value and Rt is the value from the table. For standard aluminum
capacitors a positive number indicate rejection, and for
Low ESR
values above -10. The 2nd number is the selected operating
voltage of the capacitor. It should be specified in the menu item
Large Cap/C-voltage
. It should also be kept in mind that the
measured capacitance may be significantly lower than the
original data from the data sheet due to evaporation of the
electrolyte and other degradation mechanisms. In such cases the
table cannot be used for accurate capacitor evaluation.
If you wish to measure capacitance larger than 0.9
μ
F at a
specific frequency you have to adjust frequency by pushing the
joystick to the left for one beep or select frequency in the R-L-C-
D parameter sub-menu by pushing the joystick to the right for
one beep to activate the hidden sub-menu. In this case both the
Summary of Contents for LCR-Reader MPA
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