Svantek SV 973, User Manual

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SVAN 973 User Manual
– Appendixes
150
Table C.2 Self-generated noise for different weighting filters
Electrical *) Acoustical compensated
Weighting filter A C Z A C Z
Noise < 20 dB < 20 dB < 30 dB < 25 dB < 33 dB < 48 dB
*) measured with the SL 973 microphone equivalent
Special filters
•
Windscreen compensation filter improving the instrument frequency
response in the free acoustic field when windscreen SA 22
is mounted on the microphone (see Chapter C.3)
RMS detector
•
Digital
“True RMS“ with Peak detection,
•
Resolution 0.1 dB
•
Range 327.7 dB
•
Crest Factor unlimited (for signals in 8 kHz band).
Overload detector
The instrument has the built-in overload detectors. Both A/D converter and input amplifier overload conditions
are detected. The overload in the measurement channel (in its analogue part) and the overload of the
analogue /
digital converter are both detected. The “overload” indication appears when the input signal
amplitude is 0.5
dB above the declared “Peak measurement range”.
Underrange detector
The instrument has the built-in under-
range detector. The “underrange” indication appears when the Leq
value for the elapsed time or the last second L
XY
value is below the lower linear operating range.
Time weighting characteristics (Exponential averaging)
Slow
“
S
“ according to IEC 61672-1:2013 for Class 2, Equivalent Time Constant 1000 ms
Fast
“
F
” according to IEC 61672-1:2013 for Class 2, Equivalent Time Constant 125 ms
Impulse
“
I
” according to IEC 61672-1:2013 for Class 2, Equivalent Time Constant 35 ms, Hold Time 1500 s
Reference conditions as per IEC 61672-1:2013
•
Class of the acoustic field Free field
•
Reference acoustic pressure 114.0 dB (related to 20

Pa)
•
Reference frequency 1000 Hz
•
Reference temperature +23
°C
•
Reference relative humidity 50 %
•
Reference static pressure 1013.25 hPa
•
Reference incidence direction perpendicular to the microphone diaphragm.