Casella CEL CEL-393 - Manual (Page 23)

from this displayed datum plus 63dB; ie on 30 range, answers in the span
30.1 to 93 are valid. This procedure will not affect the main digital display.
It should be noted that the instrument goes into the pause mode for
approximately 10 seconds upon range changing (35 seconds between
70 and 80dB ranges on A and B versions, 60 and 70dB on C and D
versions), to allow circuit constants to normalize. It should also be
remembered that the sound level is sampled and the various rating
parameters are computed from this data all the time the instrument is
switched on. These are known as the current period results, and they
may be reset by the key sequence 0R. This cancels the accumulated
data to date and starts a new current period.
Function
The F key selects the current period answer for display on the main digital
display. When operated without a preceeding numeral, it will bring the
current SPL value to the main digital display, which will then duplicate
the bar graph level.
The various functions calculated from current period data are selected
for display by a number code followed by the F button. These functions
are called to the display by the sequences shown in Table 2.
0F
1F
2F
3F
4F
5F
6F
7F
Answer
Maximum
L
eq
L Tm3
L Tm5
L 10
L 50
L 90
SEL
Comments Displayed
Update once per 3 or 5
second period
Or alternative values
provided by options
Only valid in event mode
Key Sequence
Mnemonic
Table 2 Keypad sequences for current period results
393 Handbook /19.