2-4
Understanding the Model 820 Keypad
Model 820 Technical Reference Manual
S
e
R/S:
This key starts and stops measurements
RESET:
Restarts a measurement by erasing
the values just measured.This function can be
used whether a measurement is in the “run”
or “stop” mode.
Enter
: used to enter new parameters selected
by the user.
U
SHIFT:
Allows access to the Orange letter
functions on the keypad.
L
EXCD: T
he Exceedance History is a record
of noise events which exceed a programmed
level for a time greater than a programmed
minimum time period. See parameters 66-70.
LOCK
: The lock functions protect instrument
data and configuration.The level of security is
configured in Setup.
M
INTV:
The Interval History provides a history
of a number of measurement values for a
moderate size time interval, 1 minute to
larger than 99 hours in one minute or greater
steps. It is programmed by parameters #72-
79.
MEM:
Memory use in percent, bytes free and
total byte available are provided as well as a
count of all of the History Records stored in
memory.
H
HIST:
The Time History function is a record
of short interval L
eq
reading and optionally, a
Peak, UWPK, or L
max
reading. The interval
can vary from 1 second to 255 minutes. His-
tory period is set by parameters #83-84.
LOG:
The Run/Stop Log is a time record of
all the actions which start or stop the data tak-
ing process of the Model 820.
Keys
Functions
