Theory
17
The cell constant can also by calculated according the following formula:
air
r
C
l
A
=
0
12
0
10
113
.
0
1
−
=
l
A
l
A
l
A
C
K
r
r
r
air
=
=
=
=
0
0
0
0
0
1
l
A
m
K
with
r
=
1
5.6
Test Instruments
There are three basic kinds of capacitance, tan
and Power Factor test instruments in use.
Although the high accuracy Schering Bridge must be balanced manually and the balance observed
on a null indicator, it has been widely sold and used for decades up until this day. The capacitance
and dissipation factor can be calculated by reading the position of the balance elements.
The automatically balanced C, tan
measuring instrument performs measurement by the
differential transformer method. The automatic balancing makes operation very easy.
The double vector-meter method is essentially an improvement of the differential transformer
method.
All three methods are in current use for accurate and repeatable measurements of C tan
on
various test objects. The differences basically lie in the resolution and accuracy. Different
instruments are generally developed specially for field or laboratory measurement.
Field instruments are specially constructed for rugged field requirements and are equipped with a
mobile high voltage source. In addition, such instruments provide noise suppression for onsite
use.
Laboratory instruments have been constructed for indoor use where high accuracy specifications
are required. These test systems are built in a modular construction for higher Test Levels. The
systems may be used for daily routine testing, for high precision long duration tests or for
acceptance tests.
Summary of Contents for 2830
Page 1: ...2830 2831 Precision Liquid and Solid Dielectric Analyzer User Manual 4843477 M Version 3 0 ...
Page 7: ...Introduction VII 17 Conformity 113 18 Notes 114 ...
Page 8: ...VIII Introduction ...
Page 121: ...Conformity 113 17 Conformity ...
Page 122: ...114 Notes 18 Notes ...
Page 123: ...Notes 115 ...