Larson Davis 824 User Manual

9/29/09 Using ID Setting Files 7-33
Hist Period (LOG, SSA)
This setting is used in conjunction
with the “Period Units Setting”
(below).
Hist Period sets the number of history period units that
transpire between successive time history samples. These
samples continue either until the instrument is stopped or
runs out of memory. This setting can include any integer
value in the following range:
(1) to (255)
Period Units - (LOG, SSA) Period Units selects the type of units the instrument uses to
calculate the time which transpires between successive time
history storage operations. To calculate the timer period, the
instrument multiplies the units selected in this setting by the
number set in Hist Period setting (see the previous “Hist
Period” setting and the following example).
Example: To measure 2 samples per second, set Hist Period to 16 and Period
Units to 1/32s (16/32=1/2).
This setting provides the following four options:
When Takt functionality is enabled,
the history period will be rounded to
the nearest 5 second interval, and a
warning, “Setting Conflict”, will
appear. If the “Period Units” equal
1/32nd of a second, then the period
will be forced to a count of 160 (5
seconds).
1/32s - This sets the History Period Unit to 1/32 sec-
ond intervals. Since the instrument samples the detec-
tor 32 times per second, this is the smallest resolution
time period that you can use. If you set the time his-
tory period to 1/32 second (i.e. period setting = 1 and
unit setting = Sample = 1/32s), the instrument will
store every sample it takes.
In the SSA instrument, the shortest
time history period is 1/8th of a
second. If the period is set to [1/32]
of a second the history period will be
forced to multiples of 4 to support
the maximum data rate of 8 samples
per second and the warning “Setting
Conflict” is displayed.
1.0s - This sets the history period unit to one second.
10.0s - This sets the history period unit to ten sec-
onds.
60.0s - This sets the history period unit to sixty sec-
onds.
Other Level - (LOG only) Use the Other Level setting to select the second
measurement level stored in each time history record along
with the L
eq
. This setting provides the following options:

Larson Davis 824 Specifications

General

Brand	Larson Davis
Model	824
Category	Measuring Instruments
Language	English