Sound Level Meter Model 831 Larson Davis |
Standard Features |
IEC 61672-1:2013, ANSI S1.4, ANSI S1.43 Class 1 integrating sound level meter |
Voice Annotation |
ANY LEVEL Display |
User programmable run modes |
Six user selectable statistics ( Ln ) |
Threshold exceedance data |
Community Noise Calculations ( Lden, CNEL ) |
GPS Global Positioning Support |
Back Erase Functionality |
Normalized Spectrum |
User-selectable screen layout and lockable setup protection |
Remote access and field upgradable |
Wide variety of non-proprietary powering options including – 4XAA internal batteries, AC, USB and external batteries |
Standards Met by Model 831 |
The Model 831 meets the specifications of the following standards : |
Sound Level Meter Standards |
IEC61672-1 Ed. 2.0 ( 2013-09 ) Class 1, Group X |
IEC60651 Ed 1.2 ( 2001 ) plus Amendment 1 ( 1993-02 ) and Amendment 2 ( 2000-10 ) Type 1, Group X |
IEC60804 ( 2000-10 ) Type 1, Group X |
ANSI S1.4-2014 Type 1 |
Octave Filter Standards ( Option 831- OB3 ) |
IEC61260 Ed. 1.0 ( 1995-08 ) plus Amendment 1 ( 2001-09 ), 1/1 and 1/3 octave bands, Class 1, Group X, all filters |
ANSI S1.11-2004 Class 1 |
Personal Noise Dosimeter Standards ( Option 831-IH ) |
IEC61252 Ed. 1.1 ( 2002-03 ) Type 1 |
ANSI S1.25-1991 Class 1 |
Safety Requirements for Electrical Equipment for Measurement, Control and Laboratory Use |
2006/95/EC Low Voltage Safety Directive |
IEC 61010-1 Ed. 3.0 ( 2010-06 ) |
EMC Immunity and Emission |
2004/08/EC EMC Directive |
IEC 61326-1 Ed. 2.0 ( 2012-07 ) |
IEC 61672-1 Ed. 2.0 ( 2013-09 ) |
FCC Title 47 CRF Part 15, Class B |
Model 831 General Features and Characteristics |
Class 1 Precision Integrating Sound Level Meter with real-time 1/1 and 1/3 octave filters |
Non-Volatile Memory |
High contrast 1/8th VGA LCD display with white LED backlight; sunlight readable |
Icon-driven graphic user interface |
Soft rubber backlit keys |
Large dynamic range |
Time weightings : Slow, Fast, Impulse, Integration and Peak simultaneously ( AnyData ) |
Frequency weightings : A, C, Z simultaneously ( AnyData ) |
1/1 and 1/3 octave frequency analysis available |
Voice message annotation and sound recording |
Ln statistics ( L0.01 through L99.9 available ) |
SLM Utility-G3 software available for set-up, control and high speed data download with export to Excel® |
Multi-tasking processor allows measuring while viewing data or transferring data |
Data Secure feature saves data to permanent memory every minute |
AC/DC outputs to recorder |
Long battery life; > 16 hours continuous measurement |
Multiple language support : English, German, Italian, Spanish, Portuguese, Swedish, French & Turkish |
Field-upgradable firmware : keeps instrument current with the latest measurement features |
Two-year limited warranty |
Sound Level Meter Specifications |
Averaging ( Integration method ) | Linear or Exponential |
RMS Time Weighting | Slow, Fast or Impulse |
Frequency Weightings | A, C or Z |
Peak Detector Frequency Weighting | A, C or Z |
Gain | 0 dB or +20 dB |
Exchange Rates | 3, 4, 5, or 6 dB with optional 831-IH |
Sample Rate | 51,200 Hz |
Peak Rise Time | 30 μμs |
Physical Characteristics |
Length with Microphone and Preamplifier | 11.35 in | 29.0 cm |
Length, Instrument Body Only | 8.8 in | 22.4 cm |
Width | 2.8 in | 7.1 cm |
Depth | 1.6 in | 4.1 cm |
Weight with Batteries, No Preamplifer or Microphone | 13.6 oz | 390 g |
Weight with Batteries, Preamplifer and Microphone | 1.2 lb | 550 g |
General Specifications |
Reference level | 114.0 dB re. 20 μPa |
Reference level range | Single large range for SLM Normal for OBA option, Gain 0 dB |
Reference frequency | 1000 Hz |
Reference direction | 0° is perpendicular to the microphone diaphragm |
Temperature | ≤ ± 0.5 dB error between +14 to +122 °F ( -10 to 50 °C ) |
Storage temperature | -13 to +158 °F ( -25 to +70 °C ) |
Humidity | ≤ ± 0.5 dB error from 30% to 90% relative humidity at 104 °F ( 40 °C ) |
Equivalent Microphone Impedance | 12 pF for Larson Davis 1/2 in microphone |
Range Level Error ( OBA option ) | ≤ ± 0.1 dB relative to the reference range |
Digital Display Update Rate | Four times per second ( 0.25 sec between updates ). First display indication is available 0.25 seconds after initiation of a measurement. |
Effect of an Extension Cable | None ( up to 200 ft or 61 m with EXCxxx cable ) |
Electrostatic Discharges | The instrument is not adversely affected by electrostatic discharges |
Extended Weather Options | -40 to +158 ºF ( -40 to +70 ºC ) operation with CER-831-E |
Resolution Specifications |
Levels | 0.1 dB |
Dose | 0.1 % |
Elapsed time | 0.1 second |
Real time clock | 1 second |
Calendar Through | 31 Dec 2100 |
Integration Time |
Time Averaged Levels and Sound Exposure Levels ( s ) |
Minimum | 0.1 second |
Maximum with Daily Autostore Enabled | Unlimited |
Maximum with Daily Autostore Disabled | > 23 days with error < 0.5 dB |
Dosimeter Metrics : TWA, Dose ( s ) |
Minimum | 0.1 second |
Maximum | Unlimited |
Ln Statistics |
Number of selectable parameters | 6 in xx.xx% format, visible on the Model 831 |
Storage of Complete Table | 0.1 dB Steps |
Spectral Statistics | Requires Octave Analysis option ( 831-OB3 ) |
Markers |
Number of Markers | 10 |
Prenamed Markers | 5 : Truck, Automobile, Motorcycle, Aircraft, Exclude |
Link Marker to Automatic Sound Recording | Yes, requires Sound Recording option ( 831-SR ) |
Back Erase |
Back Ease Time | 5 or 10 seconds |
Supported Modes | Manual |
Measurement Control Modes |
Available Modes | Manual Stop, Timed Stop, Stop when Stable, Continuous, Single Block Timer, Daily Block Timer |
Timed Stop Time in | hh:mm:ss |
Stop When Stable | Delta level in xx.x dB and time in hh:mm:ss |
Continuous with Daily Auto-Store | 1, 2, 4, 6, 12, 24, 48, 96 or 144 files per day, automated file numbering “yymmddnn.LD0” |
Continuous Restart on Power Failure | Automatic if powered by 12 VDC |
Single Block Timer | Start date and time to End data and time |
Daily Block Timer | Up to 3 blocks with each start and end date, blocks can cross date line |
Clock Stability |
<1 sec in 24 hours, at 75 ºF ( +24 ºC ) |
<10 sec in 30 days, at -40 to +158 ºF ( -40 to +70 ºC ) |
Digital Voice Annotation |
Annotate Recordings | Use headset ( ACC003 ) or measurement microphone |
Recording Sample Rate | 8 ksps |
Listening Options | On the Model 831 or using processing software for .wav files |
