Model 820 Technical Reference Manual
Stabilization Time
A-9
Stabilization Time
The Model 820 will not proceed to a running condition until it
is allowed to stabilize. At power-on, with the polarization volt-
age set to 200V or 28V, the stabilization time is approximately
45 seconds. With the polarization voltage set to 0V, the stabili-
zation time is approximately 10 seconds. A shorter stabiliza-
tion time is also invoked when certain settings (Weighting,
Detector, etc.) are changed.
Microphone Electrical Impedance
The Larson Davis ADP005 should be substituted for the 1/2"
microphone when performing electrical tests on the Model
820. The Larson Davis ADP002 is used in place of a 1/4"
microphone, and the Larson Davis ADP006 is used in place of
the 1" microphones.
Functions Measured
• L
eq
, L
max
, L
min
, TWA, SEL
• Dose, Projected Dose, Ln (1% - 99%)
• Sound Exposure in pascal squared hours (SE in Pa
2
H)
• Time History, Histograms, Measurement Time-Date-Dura-
tion
• Taktmaximal 3 and 5
• Ldn, Exceedance Events
Data Storage
• 820: 256k byte Memory
Typically, 3 month memory retention with fresh battery.