AS/NZS 61000.4.15:2012 PDF – Electromagnetic compatibility (EMC) Part 4.15: Testing and measurement techniques!Flickermeter!Functional and design specifications

AS/NZS 61000.4.15:2012 PDF – Electromagnetic compatibility (EMC) Part 4.15: Testing and measurement techniques!Flickermeter!Functional and design specifications
1 Scope and object
This part of IEC 61 000 gives a functional and design specification for flicker measuring apparatus intended to indicate the correct flicker perception level for all practical voltage fluctuation waveforms. Information is presented to enable such an instrument to be constructed. A method is given for the evaluation of flicker severity on the basis of the output of flickermeters complying with this standard. The flickermeter specifications in this part of IEC 61 000 relate only to measurements of 1 20 V and 230 V, 50 Hz and 60 Hz inputs. Characteristics of some incandescent lamps for other voltages are sufficiently similar to the values in Table 1 and Table 2, that the use of a correction factor can be applied for those other voltages. Some of these correction factors are provided in the Annex B. Detailed specifications for voltages and frequencies other than those given above, remain under consideration. The object of this part of IEC 61 000 is to provide basic information for the design and the instrumentation of an analogue or digital flicker measuring apparatus. It does not give tolerance limit values of flicker severity.
4.4 Block 3 C Weighting filters
Block 3 is composed of a cascade of two filters, which can precede or follow the selective filter circuit. The first low-pass filter eliminates the double mains frequency ripple components of the demodulator output. The high pass filter (first order, ?3 dB at 0,05 Hz) can be used to eliminate any d.c. voltage component. The values in the calibration Tables 1 a and 1 b and Tables 2a and 2b, and the performance test Table 5, include the effect of this HP filter with the 0,05 Hz corner frequency. The second filter is a weighting filter block that simulates the frequency response of the human visual system to sinusoidal voltage fluctuations of a coiled filament gas-filled lamp (60 W / 230 V and/or 60 W / 1 20 V). NOTE 1 The response function is based on the perceptibility threshold found at each frequency by 50 % of the persons tested. NOTE 2 A reference filament lamp for 1 00 V systems would have a different frequency response and would require a corresponding adjustment of the weighting filter. The characteristics of discharge and LED lamps are totally different, and substantial modifications to the calibration tables in this standard would be necessary if they were taken into account. Correction factors for several common voltage/frequency combinations are given in Clause B.2. NOTE 3 Block 3 alone is based on the borderline perceptibility curve for sinusoidal voltage fluctuations; the correct weighting of non-sinusoidal and arbitrary voltage fluctuations is achieved by an appropriate choice of the complex transfer function for blocks 3 and 4. Accordingly, the correct performance of the model has also been checked with periodic rectangular signals as well as with transient signals. Some of these signals are illustrated in the Annex B.

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