Casella CEL CEL-393 - Manual (Page 7)

i) Profile Mode
This allows the operator to set a period time. The instrument will then
calculate and store the L
eq result for each individual period, then reset
the current period answer and commence a new current period meas-
urement.
ii) Environmental Mode
Here again the required period duration is keyed into the instrument, and
at the end of each period, the CEL-393 will retain the computed L
eq , L Tm3 ,
L Tm5 , L max , and three L n values, which depending on software may be
L 10 , L 50 and L 90 . It will then reset the current period answer registers and
commence a new calculation.
iii) Event Mode
In this configuration the instrument will detect all significant noise events
by means of the exceedance of a pre-selectable threshold level. Each
event will be retained in the memory in terms of its time of occurence,
duration, maximum level and its calculated SEL (L
AX ).
iv) Frequency Analysis Mode
This memory configuration is only available when the frequency analysis
module has been fitted. When an automatic frequency sweep is made,
the level in each filtered band is stored along with the band centre
frequency and sweep start time. The results may therefore, be recalled
to the display at the end of the analysis.
All stored results are retained as long as the instrument remains pow-
ered, and may be recalled to the display by operator keystrokes as and
when required. Results may be read out at any time without affecting the
operation of the instrument. In order to maximise the availabile memory
space, a delayed start facility is provided that will allow only the required
answers to be held in store.
393 Handbook /3.