Svantek SV 973, User Manual

Page: 165 / 212

SVAN 973 User Manual
– Appendixes
165
Special filters
•
Windscreen compensation filter improving the instrument frequency
response in the free acoustic field when windscreen SA22
is mounted on the microphone (see 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. The overload in the measurement channel (in its analogue
part) and the overload of the analogue /
digital converter are both detected. The “overload” indication is 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 61252
•
Class of the acoustic field Free field
•
Reference acoustic pressure 114.0 dB (related to 20

Pa)
•
Reference frequency 1000 Hz
•
Reference temperature
+20°C
•
Reference relative humidity 65 %
•
Reference static pressure 1013 hPa
•
Reference incidence direction perpendicular to the microphone diaphragm.
Calibration
Acoustical - with the SV 34B acoustic calibrator (or equivalent):
•
Calibration level
114.0 dB (equal to the calibrator pressure level - see
calibration chart of the used calibrator)
Note:
The above levels correspond to 114 dB of calibrator’s sound pressure. If the calibrator
has a different sound pressure than 114 dB, the calibration levels must be accordingly adjusted.
Maximum peak voltage 3 V Peak-Peak (Maximum peak voltage of input sinusoidal
signal, which can be applied to the SLM without
destruction the meter)