Symbols. Abbreviations. And Definitions; Seriesandparallelcomponents - GENERAL RADIO COMPANY 1650-B Instruction Manual

1.4 SYMBOLS, ABBREVIATIONS, AND DEFINITIONS.
R~ G 1
D dissipation factor
=
-
=
-
= - =
cot 6 '
=
tan
o
The following symbols, abbreviations, and defi- X B
Q
nitions are used on the panel of the Type 1650-B and
in t h i s instruction manual:
1
for capacitors wCSRS or
C capacitance (
+ +
) w C ~ R ~
C D external decade capacitor
C o bridge residual capacitance
R R
P F power factor
=
-
=
= cos
0
R 2
+
x2
parallel capacitance
series capacitance
standard capacitor (0.1 @)
unknown capacitance
conductance (
-
),the inverse of r e s i s t a n c e
frequency
angular frequency, 27rf
ohm, a unit of resistance, reactance, or im-
pedance
kilohm, 1 kfl = 1000 ohms
multiplying factor applied t o D and Q a t fre-
quencies other than 1 kHz
megohm, 1
MR
= 1 x l o 6 ohms
microf arad, a unit of capacitance
milliohm, lrnn = 1 x 10-3 ohm
(or m p F ) nanofarad (or millimicrofarad), 1nF =
1 m p F = 1 x p F
unknown conductance
inductance
(
-
)
bridge residual inductance
parallel inductance
(or p p F ) picofarad (or micromicrofarad), I p F =
1 p p F = 1 x I O - ~ ~ F
s e r i e s inductance
henry, a unit of inductance
millihenry, 1mH = 1 x 10-3 H
microhenry, 1 pH = 1 x 10-6 H
ground, c a s e ( c h a s s i s )
unknown inductance
resistance (-), the realpart of an impedance
ratio arm resistance
standard 10 k n resistor
CGRL rheostat resistance
bridge residual resistance
1.5 SERIES AND P A R A L L E L COMPONENTS.
An impedance that is neither a pure reactance nor
a pure resistance may be represented at any specific
frequency by either a s e r i e s or a parallel combination
of resistance and reactance. Keeping t h i s concept in
mind will be invaluable for properly interpreting the
bridge results. The values of resistance and reactance
used in the equivalent circuit depend on whether a
s e r i e s or a parallel combination is used. T h e equiva-
lent circuits are shown in Figure 1-3. ' A nomograph
for series-parallel conversion a t 1 kHz i s given in the
Appendix.
parallel resistance
s e r i e s r e s i s t a n c e
DQ rheostat resistance
unknown resistance
s e r i e s reactance, the imaginary part of an
impedance
impedance
X B 1
quality factor =
-
=
-
=
-
= tan
8
= cot
6
R G D
for inductors
-
or
-
RS
w L P
Figure
1
-
3.
Equivalent circuits for complex impedonce.
I N T R O D U C T I O N
1-2