User manual

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To go to the next time period, press ‘enter’, change the start
time using the ‘next’ and ‘exit’ buttons and change the threshold
using the rotary encoder.
To go back to the preceding period press ‘undo’.
When the start times for all periods have been set, Hera
requires a few moments to store the new list.
OPTION 6: Warning and cut logic outputs
Relay outputs are triggered on time-averaged sound level
value. Time-averaged sound level is also called equivalent
continuous sound level (Leq). It is nothing more than an
averaging of each RMS sample values measured over a
certain period of time (each sample being taken every 125 mS).
This Leq value is then compared with the actual threshold and
relays are switched on or off as explained bellow.
OPTION 6.1: Enable or disable the logic outputs
This option allows you to enable or to disable the relay outputs.
OPTION 6.2: Reconnecting the AC mains supply
This option resets both relays and thus re-establishes the AC
electric supply and switches off the warning lamp.
This is the only way to reconnect the AC supply if option 6.5 has
been set to ‘Manual’.
OPTION 6.3: Warning time-averaged period
This function allows you to set up the time-averaged period
before the ‘alert relay’ signalisation is set. As soon as the
actual threshold is exceeded once, this period starts counting
and the average sound level is computed. If this average is
then higher than the threshold, the ‘alert relay’ will be switched
on and the ‘cut’ time-averaging begins. If the average is below
the threshold, nothing happens.
Adjustment range is from 10 sec to 60 sec by 10 sec steps.
OPTION 6.4: Cut-off time-averaged period
Enables adjustment of the averaging period before the ‘cut
relay’ operates. If the average sound level over this period is
higher than the threshold, the ‘cut relay’ is activated and the AC
supply is cut off. If it is lower than the threshold, both ‘alert’ and
‘cut’ relays are deactivated.
Adjustment range is from 1 min to 20 min by 1 min steps.
OPTION 6.5: Recover after period
This option is used to congure the averaging period before the
AC supply can be recovered. If the equivalent sound level over
this period is below the threshold, both ‘alert’ and ‘cut’ relay will
be resettled. If not, this period starts running again.
By choosing the ‘Manual’ option you can opt for manual reset.
In this case the PIN number must be known to enable access
to the installer menu. Option 6.2 should then be used to bring
the AC supply back on line.
Adjustment range is from 1 min to 60 min or manual recover.
LOGGING SET-UP
OPTION 7: Client’s name
This function allows you to store the client’s name in the Hera’s
memory.
Press ‘enter’, turn the encoder to select a character and press
‘enter’ again to go to the next character.
The name must be 16 characters long; all character positions
must be lled, either using a letter, number or a space.
OPTION 8: Measurement log time
As explained in the user manual, Hera logs the equivalent level
(Leq) and peak level over regular time interval. It is also the
time interval between each updating of the level indicated on
the Hera’s LED display if the LEQu display mode has been
chosen by the user.
This option allows this time interval to be adjusted. By default,
the value is 15 minutes. Adjustment range is from 1 min to 59
min by 1 min steps and from 1 hour to 8 hours by 1 hour steps.
Hera’s memory is large enough to store up 1440 log items. If
the values are stored every 15 minutes, the memory will allow
a roll-back of the 15 last days. When the memory is full, the
oldest record is replaced by the newest one. That’s what we
call a ring memory.
OPTION 9: Erase logging lists
Enables the error and events list, as well as the measurement
list, to be erased. Hera will then ask you to conrm by pressing
‘enter’ again, or ‘undo’ to cancel.