General Description - CESVA LRF-04 Manuel D'instructions

1. GENERAL DESCRIPTION

The LRF-04 frequency sound level recorder-limiter measures, displays, records and controls
the sound pressure level in the establishment where it is installed. The LRF-04 is inserted
into the reproduction chain, between the mixing desk and the crossover, intervening in the
entire sound chain.
The LRF-04 automatically corrects excesses in the musical signal level of up to 50 dB. If
these 50 dB are exceeded, the LRF-04 penalises with a 60 dB attenuation during a
programmable time interval. The wide dynamic attenuation range provides the user of the hi-
fi set with considerable room for manoeuvre in which the LRF-04 corrects the signal level
excesses without restrictive attenuations. The LRF-04 is equipped with different predictive
reply algorithms for this function, ranging from the most stable, based on the (recommended)
Leq parameter to the most restrictive, based on Leq
10s
(Extraneous Noise Override System) option, specially designed for music reproduction in
venues with a high level of ambient noise: bars, pubs etc. It does not cut out the music. In
addition, the LRF-04 has ultra-low noise outputs, perfect for acoustic shows, monologues,
recitals, etc. The LRF-04 functions according to the sound levels measured in the
establishment by means of a sensor designed on the basis of the latest technology
developed by
pressure levels in the dwelling next door to the establishment, calculated on the basis of the
levels measured by the sensor by octave bands (centred on 31.5 Hz, 63 Hz, 125 Hz, 250 Hz,
500 Hz, 1 kHz, 2 kHz, 4 kHz and 8 kHz) and to the existing insulation levels by octave bands
between the establishment and the dwelling. This spectral function allows the user to obtain
the maximum sound pressure level in the establishment without exceeding the permitted
sound level limit in adjacent buildings.
The LRF-04 is also equipped with a recording function that allows the user to store
information concerning measured sound levels in the establishment and concerning incidents
that occur (tampering with the equipment) during a minimum period of one month (Leq time
over 2 minutes, see chapter 3). The LRF-04 allows you to programme the periodicity of
information storage (from 2 min. to 1 h. in 1-min. steps). The information for each session is
also stored, allowing you to demonstrate the sound levels generated by your activity to the
authorities. The stored information may be retrieved either directly from the LRF-04, by
displaying it on the LCD screen, or by means of a printer connected to the LRF-04 parallel
port. The information may also be transferred to a PC via USB port or modem.
The LRF-04 allows the user to programme diurnal and nocturnal evaluation time zones and
the maximum levels permitted for each of the zones. These zones correspond to those
stipulated in the regulations applicable to each establishment (see example below). You may
also introduce the time when the establishment is open (session schedule) into the LRF-04,
a different one for each day of the week and adaptable to any kind of establishment. From
within the session schedule (the shaded area in the example) the LRF-04 selects the
maximum permitted level according to the time zone (day or night). Outside the session
schedule the LRF-04 attenuates 60 dB.
Monday Tuesday Wednes. Thursday
DAY
NIGHT
in the field of sound measurement and/or according to the sound
SESSION TIMETABLE
22
. The LRF-04 includes the ENOS
125 ms
Friday Saturday Sunday
08'00 h
22'00 h
07'59 h