CESVA SC-20c Manual Del Usuario página 34

L
eqT
L
eq1'
L
eq1''
Special functions
Timer
L , L , L
90 50 10
NOTE: The functions values will be refreshed on the screen each second.
Equivalent continuous sound pressure level. It is the linear average of
the square of the sound pressure during the time period of the
measurement (from Run to Stop), in decibels.
⎛
⎜
= ⋅
L 10 log
⎜
eqT
⎝
=
L
eqT
It is displayed every second. It can be A or C weighted. To display this
function turn selector 7 to the shunt position for selector 8 and selector
8 to L .
eqT
Equivalent continuous sound pressure level during 1 minute, in
decibels.
=
L
eq1'
It is displayed every minute. It can be A or C weighted. To display this
function turn selector 7 to the shunt position for selector 8 and selector
8 to L .
eq1'
Equivalent continuous sound pressure level during 1 second, in
decibels.
It is displayed every second. It can be A or C weighted. To display this
function turn selector 7 to the shunt position for selector 8 and selector
8 to L .
eq1''
It is the length of time that a measurement lasts (from Run to Stop). It
is shown in (hours-minutes-seconds) format. Due to the SC-20c's
display format, it is shown by means of a horizontal displacement
through the screen and its maximum value is 9999 hours.
To display the Timer, the measurement must be ended (Stop), i.e.,
with the display blinking. Press the button Percentiles, and while
holding it down, press the button Run/Stop. The display first shows the
Timer followed sequentially by the percentiles L
These are the levels which have been exceeded the 90%, 50% and
10% of the measurement time, in decibels.
The resolution is 0.1 dB. To calculate them the L
To display these levels the same steps should be followed as those to
display the function Timer.
⎞
T
2
1 p (t)
∫
⎟
dt
⎟
2
T p
⎠
0
0
⎛ ⎞
T
⎜ ⎜ ⎟ ⎟
− ⋅
L 10 log
E
T
⎝ ⎠
0
⎛ ⎞
60
2
1 p (t)
∫
⎜ ⎟
⋅
10 log dt
⎜ ⎟
2
60
p
⎝ ⎠
0 0
32
, L and L .
90 50 10
function is used.
F