Voltech AT5600 User Manual page 308

C H A P T E R 1 4 - A T
In the above list, items b and c will depend on the type of transformer:
For ferrite cored transformers operating at frequencies higher than
1kHz, it is preferable to measure the primary inductance and the
turns ratios between windings.
For iron cored transformers operating at the 50 or 60Hz line
frequency, where normal operation extends to the point of core
saturation, magnetizing current and open circuit voltage
measurement are normally the preferred tests.
1. Use test limits which are as wide as possible.
For example, if you are testing the turns ratio between windings where the
actual number of turns on one of the windings is only 10, specify limits of 
5% (which is equivalent to half a turn).
2. Make use of the Measure button.
For many tests, the dialogue box for the test contains a button labeled
'Measure'.
If, when you are creating your test program, you have a tester connected
to your PC, fitted with the appropriate test fixture containing a specimen
transformer, clicking on the Measure button will signal the tester to
measure the actual parameter of the test. The result will be returned to
the PC, and the Editor will insert it as the 'nominal value' in the limits
section of the test dialogue box.
This is often the best way to find the value for some of the parameters
which you may wish to test, but which do not appear on the actual
transformer design documents.
3. User Offset.
Under most circumstances, performing compensation as described earlier
will compensate all measurements for the effects of stray parallel and
series impedances, providing accurate measurements upon the part under
test.
If compensation cannot be performed conveniently or an offset is required
in the measurement is required for other reasons, then enable 'User
Offset' and enter the value to add to the result.
Enter a negative value to subtract from the measured result.
The adjusted result (including any offset) is the result that will be used to
provide PASS / FAIL judgments, and is the result that will be printed and /
or stored by the server.
4. Finally, download and run the program from the Editor, to make sure the results
are what you expect, before you use it in production.
5. The test program can be saved using the FILE/SAVE or SAVE AS future of the
editor.
The resulting ATP program file can then be moved to your chosen program
storage folder on the PC, or a network drive, for use by the AT SERVER.
Program File Names can be up to 20 characters' long
AT5600 User Manual 98-119 issue 14
E D I T O R
Page 308