CESVA SC-20e Manual Del Usuario página 34

4. AVALIABLE FUNCTIONS
In accordance to the standard EN 60651:1994/A1:1994/A2:2001
L (Peak) It is the greatest absolute value of the instantaneous sound pressure,
Cpk
L (Fast)
F
L (Slow)
S
p(t)
In accordance to the standard EN 60804:2000
L (Sel)
E
with frequency weighting C, from the beginning of the measurement, in
decibels.
To display this function turn selector 7 to L
It is the rms value with a fast exponential averaging of 125 ms, in
decibels. It is displayed every second. It can be A or C weighted.
To display this function turn selector 7 to L
It is the rms value with a slow exponential averaging of 1 s, in decibels.
It is displayed every second. It can be A or C weighted.
To display this function turn selector 7 to L
EXPONENTIAL
2
AVERAGING
( )
L
F
L
S
p(t): instantaneous sound pressure
Sound exposure level. It is the sound level which if maintained
constant for one second has an energy equivalent to the accumulated
energy during the entire measurement, in decibels.


 
L 10 log

E

p(t): instantaneous sound pressure
reference sound pressure (20 Pa)
p :
0
T: length of the measurement
T : 1 second
0
It is displayed every second.
It can be A or C weighted. To display this function turn selector 11 to
the shunt position for selector 10 and selector 10 to L
Cpk
F
S
...  = 125ms
...  = 1s

T
2
1 p (t)


dt

2
T p 
0 0
0
32
.
.
.
 
10 
log
L
2
p
0
L
p = 20Pa
0
.
E
F
S