Casella CEL CEL-63X - Manual (Page 50)

CEL-63x Environmental & Occupational Noise Meter
50 Casella CEL
Octave time constant
The setting options are for F (Fast) or S (Slow) octave time constant.
This setting defines the time weighting used to display octave or ⅓-octave band
results, and how quickly the CEL-63x instrument responds to changes in sound
pressure level.
Most measurements are made using the Fast octave time constant. When using
this setting, the instrument applies a ⅛-second (125 ms) time constant to the
sound pressure level.
Fast measurements are identified by using the subscript „F‟, for example L
AF
shows the sound pressure level using A weighting and the Fast octave time
constant.
When you set the instrument to use the Slow octave time constant, it applies a
1-second time constant to the sound pressure level.
Slow measurements are identified by using the subscript „S‟, for example L
AS
.
Measurement functions
You can select up to nine measurement functions for each user-defined
measurement view. The bottom of the screen has a counter to show how many
functions you have selected, for example “7/9”.