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6.3.
Calibration
6.3.1.
General
A high frequency voltmeter is included within the CWS 500A. This
measuring device is used for calibration purposes. The complete test set-
up, including CDN’s and cables, can be calibrated via this voltmeter.
The internal controller can compensate the frequency behavior of the test
set-up according to the requirements of IEC 61000-4-6.
For each single CDN, a Cal-file is generated and stored within the
CWS 500A. During the test in progress, this Cal-file controls the output level
of the RF-amplifier. Up to 4 Cal-files can be stored and handled in the
CWS 500A. The EM clamp as well as the current injection clamp can be
calibrated with the same method.
The advantage of this system can be explained as follows:
1. Different CDN’s, even those outside of the standard specification, can
be calibrated and used together with the CWS 500A. The internal
software of the CWS
500A will compensate the nonlinearities
automatically during each calibration.
2. The operator can calibrate the complete test set-up whenever
necessary. The operation is easy and fast.
3. Changes in the test set-up and in cabling can also be compensated.
4. The Cal function can be started by each internal program of the
CWS 500A. These Cal-files are valid for all test routines as long as the
test set-up has not been changed. Cal-files can be activated in each test
routine by pressing ”Change“.
5. If the operator needs more than 4 Cal-files he can use the ICD software
(delivered with the CWS 500A). ICD can upload the calibration data to a
computer to save them on the hard drive. The necessary files to conduct
a test can also be downloaded to the CWS 500A and stored in one of
the four memories, e.g. when a larger number of different CDN’s are
used in the same test set-up.
ICD supports nearly an unlimited number of Cal-files. The Cal-files can
be displayed graphically
For calibrations using the CWS 500A always use the internal Cal-function.
Do not use any other program. For a calibration procedure using the
CWS
500A as measuring instrument please work only with the
implemented CAL routine. Do not use other routines of the CWS 500
firmware. Use exactly the following calibration set-up.
