Casella CEL CEL-414 - Manual (Page 17)

q = 4 (C & D versions
but not CEL-414/3),
SEL Sound Exposure Level
(not CEL-266/3
CEL-328/3 or
CEL-414/3),
31-16k Octave bands centered
on indicated frequency.
Certain specialised applications require
that the one second maximum (1SM)
specified in IEC 651 para 7.8 be adopted
for the SPL function. This operating
mode may be invoked by adding a link as
described in Section 10.2. When the link
is included, an automatic indication is
given against the 1SM legend instead of
SPL, which will not be available.
Overload
The “OVERLOAD” legend appears be-
low the main digital value if any of the
overload detectors in pre- and post-
weighting, or in the RMS detector are ac-
tivated.
When SPL mode is selected, an overload
indication is given only during the actual
overload period. However, as the dwell
time is approximately two seconds the
operator can detect even brief overloads.
In memory modes, the overload indica-
tion is a latching function that can be re-
leased by performing a general reset of
the instrument as described in Section
3.3, or by resetting the relevant parame-
ter individually by pressing the RESET but-
ton.
Low Battery
When the battery voltage falls below ap-
proximately 3.2 V, the “LOW BATT” mes-
sage is displayed. This can be reset only
by switching the instrument off, replacing
the batteries, and restarting the measure-
ment sequence.
3.5Auxiliary Outputs
Two analog output signals are provided
via the auxiliary socket in the base of the
instrument (or of a CEL filter set when
connected). The “B” and “D” versions
also yield a digital output via this socket
as described in Chapter 8. Figure 4
shows the pin connections for the auxil-
iary socket.
920004
1
2
3
4
5 6
7
8
9
10
11
12
13
14
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Batt +
Batt - (0V: Instrument ground)
Not used
Un-filtered AC Out
Analog ground
AC from Filter (not CEL-266/3 & CEL-328/3)
Up function
Pause
RTS Request to send (B, D & CEL-493/3)
TXD Serial data (B, D & CEL-493/3)
Remote reset
CTS Clear to send (B, D & CEL-493/3)
Log. DC out
Event in progress (only CEL-493/3)
Figure 4: External view of auxiliary socket
General CEL Sound Level Meters Handbook - Page 13