Casella CEL CEL-414 User Manual
Page 27
connecting link has been fitted as de-
scribed in Section 10.2.
1. 1SM measurement is selected auto-
matically at the end of the self test
instead of SPL when the link is in
place, otherwise use the FUNCTION
buttons to step the arrow marker
round the display to 1SM.
The digital display will show the 1SM
profile level (updated every second),
while the analog bar continues to
show the sound pressure level.
6.4Duration of Measure-
ment Period - DUR
1. Use the FUNCTION buttons to step
the arrow until it points to DUR.
The time elapsed since the instrument
last experienced a general reset or
function reset will be shown on the
digital display with an accuracy
better than 5 s in 24 hours.
The analog display continues to show
the instantaneous sound pressure
level.
6.5Measurement of Maxi-
mum Value - L
max
1. Use the FUNCTION buttons to step
the arrow until it points to MAX.
The highest sound pressure level
measured during the period since
the L
max
register was last reset will
be shown on the digital display with
a resolution of 0.1 dB.
This level is updated each time a new
maximum is reached, and does not
decay with time as it is stored
digitally.
2. Reset the L
max
register either by
means of a general instrument reset
(see Section 6.1, step 7 above), or
by pressing the RESET button while
MAX is selected for display
(Section 6.1, step 8).
Refer to Sections 3.2 and 3.3 for
further information on the reset
possibilities.
The analog bar graph always shows
the instantaneous sound pressure
level.
6.6Measurement of
Equivalent Continuous
Level - L
eq
(not
CEL-328/3E or CEL-414/3C)
Measurement of broadband L
eq
is not
possible with CEL-328/3E, which can
measure L
eq
only in octave bands (see
section 6.10).
1. Use the FUNCTION buttons to step
the arrow until it points to LEQ.
The choice of a time weighting will
probably be governed by the need to
obtain a maximum L
max
value during
the same period, so fast or slow
time weightings are normally
selected.
However a value for the impulse
weighted average value L
AIm
can be
obtained when impulse weighting is
selected.
The equivalent continuous level
measured during the period since
the L
eq
register was last reset will be
shown on the digital display with a
resolution of 0.1 dB, while the
instan- taneous sound pressure level
is indicated by the analog display.
All
Except
328/3E
414/3
General CEL Sound Level Meters Handbook - Page 23