Casella CEL CEL-393 - Manual (Page 5)

1. INTRODUCTION
Thank you for choosing the CEL-393 Precision Computing Sound Level
Meter.
CEL experience in both Acoustics and Data Processing combine to
produce a full specification computing sound level meter to assist engi-
neers in the control of excessive noise and vibration. The latest advances
in micro-electronics have been employed to reduce the size of the
instrument considerably, whilst the on-board microprocessor simplifies
its operation and extends the facilities provided.
The CEL-393 represents the new concept of a sound and vibration
analysis laboratory in a slim line 'pocket-sized' package that is equally
at home in the evaluation of environmental noise nuisance or the
assessment of noise deafness risk in industry. Within the compact
dimensions of the CEL-393 are to be found a wide range of functions
that were previously available only with bulky laboratory systems.
The instrument has a 63dB dynamic range with an on-board computer
controlling the custom designed display to provide both conventional
analogue and fully annotated digital results. It will compute and store a
wide range of noise rating descriptors including four L
eq based units,
three L n values plus the maximum value. Both conditioned AC and Log
DC outputs are provided to feed ancillary instruments such as tape and
graphic level recorders.
Fitting the optional filter module allows both octave and third octave band
analysis to be undertaken, either manually, or with a high level of
automatic control. This is achieved either by passing command to the
internal microprocessor or by an external device such as the CEL-160
Graphic Recorder. The filter option also provides a general purpose
digital output suitable for use with the CEL-238, -338, -438 family of
Digital Processor/Printers, or to a wide range of conventional computers.
In normal operation the instrument is in the current mode, and will
indicate the current SPL level on both its analogue bar graph display and
393 Handbook /1.