Author Topic: Levelcheck dB(C) Question  (Read 363 times)

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Maiskolben

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Levelcheck dB(C) Question
« on: October 30, 2016, 20:43 »
Dear guys,

I have a problem when I calibrate with comparing measurement method. After I just finish my sinus at 1kHz, the little dB(C) field is showing a value about 10dB higher than my average PCE 322-A. So when I'm taking a measurement, my PCE is showing alway ten dB less than the dB(C) (actual value) field. Any suggestions about that?

It could be, that Levelcheck is taking the peak and my PCE is taking rms, couldn't it?

TomyN

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Re: Levelcheck dB(C) Question
« Reply #1 on: October 30, 2016, 23:14 »
Hi,

the difference in Level (if we assume a sine wave 1kHz tone) between peak and rms-values (also known as crest - factor) should be 3dB.
I assume that some is going wrong during the calibration process.

Tomy
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DANTE Level1 certified

Maiskolben

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Re: Levelcheck dB(C) Question
« Reply #2 on: October 31, 2016, 00:36 »
Hey Tomy, thanks for the quick response! You mean, my PCE is measureing rms values in slow and dB(C) mode, and levelcheck does peak (the field with dB(C) actual) values? Is that right?

TomyN

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Re: Levelcheck dB(C) Question
« Reply #3 on: October 31, 2016, 07:33 »
Hi,

yes. The weighting curves do not affect the result at 1kHz and the crest - Faktor of a sine - wave is 3dB.
So if you measure a 1kHz sine - wave then the results differ by a maximum of 3dB (depending on the averaging time settings of the displays). Measuring other waveforms (or broadband signals as music or pink - noise) will yield larger differences, depending on the waveform.

Tomy
Dipl.-Ing.(FH) Thomas Neumann
SIM-II Operator
DANTE Level1 certified