Sound Level Meter Model 831C Larson Davis

Standards Met by Model 831C

The Model 831C meets the specifications of the following standards :

Sound Level Meter Standards

IEC61672-1 Ed. 2.0 ( 2013 ) 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 Class 1

ANSI S1.43-1997 Type 1

DIN 45657

Octave Filter Standards ( Option 831C- OB3 )

IEC61260 Ed. 2.0 ( 2014 ) Class 1, all filters

ANSI S1.11-2014 Class 1, all filters

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

Sound Level Meter Specifications

Averaging ( Integration Method )

Linear or Exponential

Time Weightings

Slow, Fast,or Impulse

Frequency Weightings

A, C, and Z

Peak Detector Frequency Weighting

A, C, or Z

Gain

0 dB or +20 dB

Sample Rate

51,200 Hz

Peak Rise Time

30μs

Metrics Measured

Leq, Lmax, Lmin, Lpeak, Ln ( 6 values ), LDN, LDEN,LCeq–LAeq

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

17.3 oz

490 g

General Specifications

Reference Level 

114.0 dB re. 20 μPa

Reference Level Range 

Single large range for SLM measurements

Reference Frequency 

1000 Hz

Reference Direction  

0° is perpendicular to the microphone diaphragm

Operating Temp.

≤ ± 0.5 dB error between -22°F to +122 °F ( -30 °C to 50 °C )

Storage Temp.

-40 °F to 176 °F ( -40 °C to 80 °C )

Humidity

≤ ± 0.5 dB error from 30% to 90% relative humidity at 104 °F ( 40 °C )

Equivalent Microphone Impedance 

12 pF

Effect of an Extension Cable 

None up to 200 ft ( 61 m ) with EXCxxx cable

Approvals 

CE, ROHS, WEEE

Extended Weather Options 

-40 °F to +158 ºF ( -40 °C to +70 ºC ) operation with CER-831-E

Resolution Specifications

Levels 

0.1 dB

Elapsed Time 

0.1 s

Real Time Clock 

1 s

Integration Time

Time Averaged Levels and Sound Exposure Levels

Minimum 

0.1 s

Maximum with Daily Autostore Enabled 

Unlimited

Maximum with Daily Autostore  Disabled 

> 23 days with error < 0.5 dB

Ln Statistics

Number of Selectable Parameters 6 in xx.xx % format

Distribution Resolution 0.1 dB

Spectral Statistics Requires Octave Analysis option ( 831C-OB3 )

Markers

Number of Markers 

10

Prenamed Markers 

Truck, Automobile, Motorcycle, Aircraft, Exclude

Back Erase

Back Erase Time 

5 or 10 s

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”

Restart after Power Failure 

Automatic if powered by 12 VDC and continuous run mode

Single Block Timer 

Start date and time to end date and time

Daily Block Timer 

Up to 3 blocks between each start and end date

Clock Stability

< 1 sec in 24 hours, at 75 ºF ( +24 ºC )

< 10 sec in 30 days, at -40 °F to +158 °F ( -40 °C to +70 °C )

< 1 s when using NTP