Series CT Automatic Test System Highlights
Traceability to international standards
Accuracy is traceable to the National Research Council of
Canada. A calibration certificate is on file. A certified CT is
supplied with the test system. This certified CT is used as a
transfer standard. The transfer standard should be tested
periodically and the system test data compared to the transfer
standard calibration data. Certification software is included to
calibrate the test system if necessary to assure compliance with
the transfer standard data. The certification of the transfer
standard may be updated by the user if required.
When the data save function is enabled, all CT identification
data, test result data and all test program data are saved on disk
at the conclusion of each completed test sequence. The data
are saved in CSV format so each data line is a record of one
RCF and Phase test. This data is saved in the CT Saved Data
folder. One file is opened for each date, and records are
appended to the file as the day progresses. The user can
retrieve data externally by network or add Microsoft Access or
Excel for local use.
Test program data is saved in the CT Test Program Data folder.
One file is opened for each CT; the file name is the CT part
number. The program data is saved as ASCII text strings
separated by CReturn‘s. Test program data files may be added
or edited off line with a network connection. If this is planned,
the user should verify any external test programs in advance,
as the system will trap any illegal or ambiguous text, display
error messages and prevent its use until corrected.
The ANSI Parallelogram
(Phase Limits per ANSI C57.14)
If ANSI accuracy classes of 0.3, 0.6 or 1.2% are
programmed, and if the Test Level is 100% or 10%
then the phase limit data fields will display “ANSI”’.
In this case, the High and Low Phase limits will be
automatically calculated at test time according to the
table below. This table is specified in ANSI C57.13.
If the programmer replaces the phase limit display of
“ANSI” with a numeric value, then the value will be used
as the phase limit and the auto limit calculation disabled.
Since the auto phase limits are derived from the actual
RCF measurement, auto phase limit calculations will be
done during the test cycle, after the measurement, but
before the PASS/FAIL comparison. If the RCF
measurement is over either RCF limit, the phase limits
will be automatically set to the phase values in the table
corresponding to the maximum RCF limit.