The definition of measured field, voltage and current

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joro
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The definition of measured field, voltage and current

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The definition of measured field, measured voltage and measured current
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joro
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Re: The definition of measured field, voltage and current

Post by joro »

From RadiMation version 4.3.9 and upward, the measured field, measured voltage and measured current are always displayed as corresponding non-modulated test-levels. The measured values are corrected for the applied modulation and the possible applied modulation conservation.

The reason for the displaying of corrected measurement data is caused by the specification of test levels in the standards. Every standard is specifying the testlevel in the unmodulated CW-values. When also modulation should be applied, this is separately specified in the standard. A more specific requirement for voltage or power conservation of the modulation can also be specified. If modulation and possibly conservation is applied, this will result in a different measurement value which will be displayed in the graph. In that situation the graphs will show a higher or lower test-level compared to the test-level specification from the standard. When the measured values are corrected for the applied modulation and the possible applied conservation, the displayed values in the graphs will be corresponding CW values, which will be directly comparable to the test-level specifications from the standard. The displaying of the corrected measurement values will thus prevent a lot of confusion between the measurement values and the test-level specification in the standards.

An example: in a radiated immunity substitution test with no modulation with a test-level of 10 V/m, the measured field strength will be 10 V/m, and this value will also be displayed. If the same test is performed with 80% AM Modulation, a field strength of 18 V/m will be measured. In this case the software will however display 10 V/m, because that is the requested test-level. The displayed values are still measured values, but the measured values are corrected for the applied modulation. The graphs are also corrected to show the the relevant level if conservation of the modulation is used. So if during the above example also voltage conservation of the modulation is selected, the carrier level will be 5.1 dB lower. The measured field strength will be 10 V/m again, and the graph will also display 10 V/m. As a result of this implementation, in an optimal situation, the values of calculated field, measured field and specified test-level should be displayed at the same values in the graphs.

Also the graphs for the field, voltage and current levels are corrected for the applied modulation and conservation. The corrections on the measured values are depending on the ability of the used measuring device to correctly measure a value when modulation is applied. If for example a field strength sensor makes an error during the measurement of the electrical field when modulation is also applied, the corrected and displayed value of the measured field strength will also not be accurate.
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joro
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Re: The definition of measured field, voltage and current

Post by joro »

In addition to previous explanation, there is one important remark regarding the display of the power graphs.

As explained in the previous post, the values that are shown in the field, voltage and current graphs are corrected for the modulation and the conservation. However, this is NOT done for the forward-, reflected- and net-power graphs in singleband immunity. When the implementation in version 4.3.9 of RadiMation changed, it would have been to confusing to change the display of the power graphs, as it would make it very confusing to compare the power graphs of the versions before and after the 4.3.9 version.
The forward-, reflected- and net-power graphs in the singleband immunity are thus not corrected for the applied modulation and conservation.

The multiband immunity module was however created after the 4.3.9 version of RadiMation. When the multiband immunity module was implemented, we were aware of this problem, and we then decided to also use the same definition for the power graphs in the multiband immunity module. In multiband immunity the forward-, reflected- and net-power are thus corrected for the applied modulation and conservation.

If modulation out of the dwell-time, or modulation with conservation is used, this will thus result in a difference between the forward-, reflected- and net-power graphs between the singleband and multiband immunity tests. The tests are performed in the same way with the same powerlevels, however the display of the powerlevels in the singleband immunity tests are showing the uncorrected power graphs.
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