Model 831 Manual
Setup Tabs
4-5
Integration Method
Note that the Model 831 can be set to
run for a preset integration time as
described in "Manual Stop, Timed
Stop or Stop When Stable" on page
6-4
Two Integration methods are available: Linear and
Exponential.
Exponential Integration
Exponential integration is provided mainly to provide
compatibility with older instruments. Exponential detectors
have a tendency to hide small events in the long decay of a
loud impulsive event.
Note that when performing time history measurements using
time increments 10 ms or less, the integration method must
be linear. If exponential integration has been selected at the
time of setup, this will be changed as described in “Linear
Integration Only” on page 11-6.
Linear Integration
Linear integration integrates only energy that occurs during
a given time period and therefore does not exhibit the decay
slope of a Fast, Slow or Impulse exponential detector.
The value of the integrated level is displayed immediately
following the end of the integration time.
For long duration measurements both integration methods
report the same value in that they both have equivalent
“energy under the curve”, although short term metrics may
vary.
20 dB Gain
When measuring low level sounds, when the sound level is
approaching the background noise level of the instrument, it
is recommended to increase the gain by 20 dB. This is done
by using the
2
key to highlight this section and pressing
5
to insert a check. Press
5
again to remove the check
and set the gain back to 0 dB
The effect of the gain on the noise level is shown in
FIGURE A-27 "Noise of Model 831 with 377B02: 0 dB
Gain, Low Range” on page A-48, FIGURE A-28 "Noise of
Model 831 with 377B02: 0 dB Gain, Normal Range” on
page A-49, FIGURE A-29 "Noise of Model 831 with
377B02: 20 dB Gain, Low Range” on page A-50 and
FIGURE A-30 "Noise of Model 831 with 377B02: 20 dB
Gain, Normal Range” on page A-51.
Summary of Contents for 831
Page 1: ...Model 831 Sound Level Meter Manual...
Page 2: ...I831 01 Rev O Manual Larson Davis Model 831 Manual...
Page 123: ...5 44 Any Level Display Model 831 Manual...
Page 135: ...6 12 Run Modes Without Measurement History Model 831 Manual...
Page 155: ...7 20 Recovery After Improper Shutdown Model 831 Manual...
Page 209: ...11 22 Markers Model 831 Manual...
Page 221: ...12 12 Link to Time History Model 831 Manual FIGURE 12 11 Time History Display...
Page 321: ...16 24 Sound Recording Playback Model 831 Manual...
Page 358: ...Model 831 Manual Displays 18 27 FIGURE 18 42 Measurement Displays FIGURE 18 43 Events Displays...
Page 403: ...20 28 Troubleshooting Model 831 Manual...
Page 413: ...21 10 Calibration When The Model 831 Is Locked Model 831 Manual...
Page 421: ...23 4 File System Model 831 Manual...
Page 501: ...A 64 Vibration Sensitivity Model 831 Manual...
Page 513: ...B 12 Sections 5 6 7 and 9 except 9 3 Model 831 Manual...
Page 525: ...C 12 Community Noise Descriptors Model 831 Manual...