Effects of the A‐weighting tolerance limits on rms measurements Free

The effects of type 1 A‐weighted tolerance limits on rms measurements have been investigated theoretically and verified experimentally. Three A‐weighted circuits, each of which satisfied type 1 tolerances, were tested with pulse trains with various crest factors; and depending on the frequency‐band limits of the measuring system, erroneous rms readings could be obtained. For example, at a constant repetition rate of 10 kHz and a crest factor of 3, the measured rms readings obtained with the A‐weighted circuits spanned a range of 4 dBA when the frequency‐band limit was increased from 30 to 100 kHz.