Svantek SVAN 958A - Page 203

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SVAN 958A User Manual
1/1 octave and 1/3 octave filters
1/1 Octave 15 filters with centre frequencies from 1 Hz to 16 kHz (base 2). meeting
DIN 45651. IEC 1260 (Annex B) and ANSI S1.11-1986 for Type 1
1/3 Octave 45 filters with centre frequencies from 0.8 Hz to 20 kHz (base 2). meeting
DIN 45651. IEC 1260 (Annex B) and ANSI S1.11-1986 for Type 1
See Chapter C.3.3 for filters characteristics.
Linear operating ranges
Two measurement ranges are available (for all available channels): Low and High
Table C.3.1. Linear operating ranges with SV 12L preamplifier and ST 02 adapter
Range
Linear operating ranges (with the error  0.7 dB)
(RMS for the sinusoidal signal at reference conditions @ 1 kHz,
0.0 dB calibration factor and microphone sensitivity 50 mV/Pa)
Low
from 24 dB “A” - weighting
to 115 dB “A” - weighting
from 24 dB “C” - weighting
to 115 dB “C” - weighting
from 30 dB “LIN” - weighting
to 115 dB “LIN” - weighting
High
from 44 dB “A” - weighting
to 137 dB “A” - weighting
from 42 dB “C” - weighting
to 137 dB ”C” - weighting
from 46 dB “LIN” - weighting
to 137 dB “LIN” - weighting
Table C.3.2. Linear operating ranges with different filters in analyser modes for PEAK value
Range
Linear operating range PEAK (for the microphone
sensitivity 50 mV/Pa)
Max PEAK value
Low
118 dB “A” - weighting
118 dB “C” - weighting
118 dB “LIN” - weighting
High
140 dB “A” - weighting
140 dB “C” - weighting
140 dB “LIN” - weighting
Note: For the signals with the crest factor n >1.41 upper measuring range of the RMS (LEQ and
SPL) is reduced. The valid upper limit can be calculated according to the below given formula:
, where A is the upper limit for the sinusoidal signal.
Example: For the crest factor n = 10 the upper limit is A
10
= 120 dB.
( )
2log20137 nA
n
−=