Svantek SV 977D User Manual

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SV 977D User Manual - Appendixes
Ovl
Percentage of the overloaded input signal, which occurred during the current time period of
the measurement (T)
Peak
Maximum absolute value of the signal
calculated for the given T
( )
tamaxPeak
WT
=
P–P
Peak-to-peak (P-P) result is the
difference between highest and lowest
value of the signal calculated for the given
T
( )
( )
( )
( )
ta,0minta,0maxPP
WTWT
− = −
Max
Maximal value of the time-weighted signal
for current time period of the
measurement (T)
( )
( )
tamaxMax
W
T

=
RMS
RMS (root mean square) result for current
time period of the measurement (T)
( )

=
T
0
2
dttv
T
1
RMS
D.3. STATISTICAL LEVELS – LN DEFINITION
The noise level L(t) is the continuous random variable. The
probability that the temporary noise level L(t) belongs to the
interval
LL,L
kk
+
is called the class density and it can be
expressed by the equation:
( )  
PtLLtLLP
n
1i
ikkk

=
 =  +  
where:
i
t

- time intervals, in which the noise level
( )
LL,LtL
kk
+
occurs,
L
- so-called class interval or distribution
class of the series,
P
- total observation period.
In case when the class interval approaches infinity, the probability of L(t) tends to the probability of
k
L
. In
practice,
L
value is strictly determined for the measuring instrument. For SV 977D, there are 240 classes
and the width of each class is 0.5 dB. The histogram is the set of the class density values calculated for all
classes.
The statistical distribution function, which determines the
probability (expressed in %) of the noise occurrence on the
level equal or less than
LL
k
+
is given by the formulae:
( )
 
( )

=
=
j
1k
kj
LPLtLP
The cumulative density function, expressed by the equation:
is directly used to determine so-called statistical levels Ln or
position parameters of the distribution.
( )
 
( )
 
jj
LtLP1LtLP −=
The Ln is the certain boundary level surpassed by the temporary noise level values in not more than n% of
the observation period.

Svantek SV 977D Specifications

General

Brand	Svantek
Model	SV 977D
Category	Measuring Instruments
Language	English