Casella CEL CEL-393 - Manual (Page 9)

2 SCHEDULE OF PARTS
The CEL-393 is available without or with its frequency analysis and digital
interface module, and identified as the A and B models respectively. Both
of these versions are equipped with the CEL-186 series microphone.
Two other versions for the measurement of very low sound levels are
also available. These employ the CEL-190 high sensitivity microphone
which lowers the measured levels by 10dB. When this microphone is
supplied the units are designated CEL-393C (without filter and interface)
and CEL-393D (with filter and interface) respectively.
Throughout this manual, reference to CEL-393 indicates that comments
apply to both the A and B versions, while references to CEL-393B, for
example, apply only to that version of the instrument. Similarly, descrip-
tions of the A version also apply to the C version and of the B to the D
unless stated to the contrary.
Instruments that have the filter board fitted as original equipment have a
B or a D added to the end of the serial number. The presence of the filter
in an instrument is best detected by selecting either the octave or third
octave filter positions on the filter switch (Figure 4). If the module is not
present the bar graph will not operate, and the mnemonics for frequency
bands will not appear.
Instruments are provided with the three L n values normally set to L 10 ,
L 50 and L 90 . However, a number of variants are available as optional
initial equipment or as retrofit programs: they are listed in Table 1.
The program installed in each individual instrument is noted both on the
calibration certificate contained in Chapter 12 as the ROM part number,
and on a label fitted to the rear of the instrument adjacent to the battery
cover (Figure 2). The last two digits of this code are the software issue
number, and hence they will be revised upwards as improvements are
included. In the absence of any of this information the software variant
may always be deduced from the L
n mnemonics that appear on the
display.
393 Handbook /5.