Voltech ATi User Manual page 305

More Tests
A comprehensive suite of more than 20 different tests is available for the ATi,
and new tests are constantly being developed. Additional tests can be
purchased at any time, and are available on disk or by e-mail, so that your ATi
can be upgraded in a few minutes with the aid of the Voltech Editor software
running on a PC. The tests available at the time of printing are listed in the
next section of this chapter. Check with your Voltech supplier or on the Voltech
website at www.voltech.com for the up-to-date list.
Iron Core Transformers
For iron core transformers operating at 50/60/400 Hz, Voltech recommends
the use of a magnetizing current test rather than inductance. This test is
available only on the Voltech AT3600.
Hi-Pot or 'Flash' Testing
Transformers are often used to provide safety isolation between the AC line
and the user. Where this is the case, very high voltages (2000 to 5000VAC)
must be used to test this isolation. The Voltech AT3600 incorporates this test
as well as all of those available for the ATi and more.
Self Resonant Frequency
Practical inductive components are not perfect inductors; they have stray
resistances and capacitances associated with them. For certain components,
especially those with a low inductance value, the impedance of the stray
capacitance can become significant when compared to that of the inductance.
1
= Π
=
X 2 fL X
Π
L
C
2 fC
At a sufficiently high frequency, the capacitive impedance can dominate,
making a measurement of the inductance impossible. Under these
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