Model 820 Technical Reference Manual
Setting and Viewing Advanced Functions
7-9
• 64 - Uwpk Excd Level - Unweighted peak exceedance
level.
• 65 - Excd Hysteresis - (0-9)
After an exceedance, the level must
drop this amount below the
exceedance threshold before a new
exceedance is logged. This pre-
vents multiple exceedance for a
single event if level fluctuates
about the threshold.
The Exceedance History parameters, items 66-70, allow you
to select and define what data are to be saved in memory dur-
ing an exceedance.
Each exceedance indicates the time it started, durations, sym-
metry, L
eq
, SEL, L
max
, Peak, and Time History (if desired).
Step 1
Press
R
and
L
to access item 66 from the pre-
vious field, or press
R
,
m
,
66
, and
e
.
Here is a brief explanation of each parameter:
• 66 - Excd Enable - [Yes, No]
[Yes} would insure the exceedance
report will be stored in memory
when exceedance conditions 61-65
are met.
• 67 - Excd Exchange - [3dB, 4dB, 5dB, 6dB]
Used to calculate exceedance inte-
grated level and normally set at 3
dB (L
eq
). 4 dB gives L
DOD
, 5 dB
gives L
OSHA
, 6 dB gives L
avg
.
• 68 - Ex Min Duration - (0-255)
This parameter sets the minimum
duration in seconds of exceedance
records.
• 69 - Excd Time Hist - (Yes, No)
With this item set to (Yes), a time
history is saved only during the
time an exceedance event occurs.
• 70 - Excd Hist Per n/32 - (0-255)
The exceedance time history sam-
ple period is in 1/32 seconds. Ten
samples before and after the
exceedance are normally stored,
up to a maximum of 255 samples.
