Casella CEL CEL-281 - Manual (Page 52)

If the logging run is still in progress, the display is dynamic and may be seen to
increment to new values.
Note : The time constant used for the L )8/ value displayed is the constant set at the
time the data was logged.
While average noise levels are being displayed, pressing the
key allows the results to be obtained from four different
exchange rate values (Q). The value in current use will be
shown against the Q legend on the display. (Remember that
L
eq is the L AVG value calculated with Q = 3.)
While average noise levels are being displayed, pressing the
key selects the next from a series of up to five threshold
levels for use in the calculation. The newly selected threshold
level will be shown on the display. Then pressing the key
again returns to the average noise level that was being in-
spected, but now shows it calculated with the new threshold
level.
All five threshold levels should be available, but if the criterion
level has been set to a value lower than 90 dB, only threshold
levels
≤ the criterion level will be available as described in Sec-
tions 2.2.2 and 2.2.3. Therefore when a threshold level is re-
quired that is higher than those currently available, the criterion
level must be increased even though it has no part in the par-
ticular L
AVG calculation.
While Fast or Slow maxima are being displayed, pressing the
key displays the time at which the maximum level oc-
curred. Pressing again shows the date at which the maxi-
mum occurred. Then pressing the key twice (or once)
returns the display to the previously indicated maximum level.
How It Works
Page 44 - CEL-281 Operator's Handbook