13
It is best to check with the component manufacturers’ data sheet to determine the desirable D value of a good
component.
Measuring Capacitance of Cables, Switches or Other Parts
Measuring the capacitance of coaxial cables is
very useful in determining the actual length of the cable. Most manufacturer specifications list the amount of
capacitance per foot of cable and therefore the length of the cable can be determined by measuring the
capacitance of that cable.
For example: A manufacturers, specification calls out a certain cable, to have a capacitance of 10 pF per foot,
After measuring the cable, a capacitance reading of 1.000nF is displayed. Dividing 1000pF (1.000 nF) by 10 pF
per foot yields the length of the cable to be approximately 100 feet.
Even if the manufacturers’ specification is not known, the capacitance of a measured length of cable (such as 10
feet) can be used to determine the capacitance per foot. Do not use too short length such as one foot, because
any error becomes magnified in the total length calculations.
Sometimes, the affecting stray capacitance of switches, interconnect cables, circuit board foils, or other parts,
could be critical to circuit design, or must be repeatable from one unit to another.
Series Vs Parallel Measurement (for Inductors)
The series mode displays the more accurate measurement in
most cases. The series equivalent mode is essential for obtaining an accurate Q reading of low Q inductors.
Where ohmic losses are most significant, the series equivalent mode is preferred. However, there are cases
where the parallel equivalent mode may be more appropriate. For iron core inductors operating at higher
frequencies where hysteresis and eddy currents become significant, measurement in the parallel equivalent
mode is preferred.
1.4 Accessories
Operating Manual
1 pc
AC Power Cord
1 pc
Kelvin Clip
1 pc
DMM Test Leads
1 pc
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