Model 820 Technical Reference Manual
Features
1-5
Especially important information is shown in italics, for
example:
Features
The Larson Davis Model 820 meets the requirements of the
American National Standards Institute (ANSI) S1.4,
International Electrotechnical Commission (IEC) 651, and
804-1985 standards for
Type 1
accuracy and offers the
following features:
• Dynamic range of more than 100 dB for error free mea-
surements.
• Impulse measuring range greater than 100 dB.
• Standard microphone allows measurements typically
between 30 and 140 db(A) in one range. Optional micro-
phones allow measurements as low as 20 dB or as high as
190 dB(A). Mic. bias is user selectable: 0, 28, and 200 V.
• Selectable A and C frequency weightings for hearing pro-
tector applications.
• Multiple detectors provide simultaneous RMS and PEAK
measurements.
• L
eq
integrated level (duration ranging from 1 second to 99
hours, manually controlled).
• Measures FAST, SLOW, Unweighted PEAK, Weighted
PEAK, Impulse, L
eq
, L
DOD
, L
OSHA
, Dose, Projected Dose,
TWA, Sel (L
ae
), L
max
, L
min
, six user defined L
n
s, L
dn
,
CNEL, and more.
• User selectable dose exchange rate, criterion, threshold,
and reference duration.
• Measures and stores more than 40,000 different DOSE
To access items 48-50,
Overall Exchange Rate,
Overall Threshold
,
Overall Criterion
, press the
d
key.
