Precision sound level meter LD-831 C.

  • Class 1 precision sound level meters (IEC 61672-1: 2013, ANSI S1. 4-2014),
  • High resolution LCD colour display,
  • Real time-frequency analysis in 1/1 and 1/3 octave bands IEC 61260:2014 and ANSI S1. 11-2014 class 1,
  • Frequency weighting: A, C, Z at the same time,
  • Voice & sound recording
  • 2 GB of internal memory, expandable via USB,
  • Data sharing and remote control via 4 G, WiFi or LAN
  • With METAS, PTB approval Class 1
basic data
Averaging (integration method) Linear or exponential
RMS-term review Slow, fast or pulse
frequency A, C or Z
Peak Frequency A, C or Z
reinforcement 0 dB or +20 dB
doubling rates 3, 4, 5 or 6 dB with option 831-IH
sampling rate 51,200 Hz
Rise time (peak value) <span≤30 µs
reference level 114.0 dB re. 20 uPA
Reference level range One big area for SLM Normal Option OBA, Gain 0 dB
reference frequency 1000 Hz
reference direction 0 ° is perpendicular to the microphone diaphragm
temperature ≤± 0.5 dB error between -10 ... 50 ° C
storage temperature -20 ... 70 ° C
humidity ≤± 0.5 dB error of 30 ... 90% RH at 40 ° C
Equivalent impedance microphone 12 pF for 1/2 "microphone Larson Davis
Field level error (option OBA) ≤± 0.1 dB relative to the reference region
Refresh rate of the screen Four times per second (0.25 seconds between updates). 
The first display is 0.25 seconds after initialization of the meter is available.
Impact of an extension cord No effect (up to 61 m with EXCxxx cable)
Electrostatic discharges The device is not adversely affected by electrostatic discharge.
Extended weather options -40 ... +70 ° C with CE-831-E
level 0.1 dB
dose 0.1%
Elapsed time 0.1 s
Real Time Clock 1 s
calendar Until December 31, 2100
integration time
Time-averaged values ??and sound exposure level (s)
   minimum 0.1 s
   Maximum active daily 
   Maximum daily with inactive 
> 23 days with <0.5 dB error
Dosimeter measurements: TWA, noise dose (s)
   minimum 0.1 s
   maximum Unlimited
In statistics
Number of selectable parameters 6 in the format xx, xx%, visible on the model 831c
Storing the complete table 0.1 dB steps
Spectral statistics Requires octave analysis option (831c-OB3)
Number of markers 10
already numbered with names marker 5: truck, passenger car, motorcycle, plane, exclusion (of the measurement)
Backward-delete function
Backward erase time 5 or 10 seconds
Supported modes Manually
Control modes for the measurement
existing modes Manual stop, timed stop, stop if stable, continuous, single-block timing, daily block timing
Timed stop Time in hh: mm: ss
Stop if stable Level difference in xx.x dB and time in hh: mm: ss
Continuously with daily automatic storage 1, 2, 4, 6, 12, 24, 48, 96 or 144 files per day, automated file number 'yymmddnn.LD0'
Continuous restart after power failure Automatically at 12 V DC
Single block timing Start: date and time; End: date and time
Day Block Timing Up to 3 blocks with each start and end dates, blocks the dateline may exceed
term stability
stability <1 s in 24 hours at 24 ° C 
<10 s in 30 days (-40 ... 70 ° C)
Digital voice comment
comment records With headset (ACC003) or measuring microphone
Sampling rate of the recording 8 ksps
monitoring options Model 831c or processing software for .wav files
AC / DC output
Rifle 2.5 mm, for cable CBL139
AC output - voltage range ± 2.3 V pk  maximum 0.5 ... 1.6 V mV rms  sinusoidal
AC output - Recommended load headset; Speaker impedance> 16 ?
DC output - voltage scale 10 mV per dB, 100 dB for 1 V
DC output - frequency and time Correspond to the SLM settings: A, C or Z and S, F or I
Signal tap the preamplifier With ADP015 and EXC006
power supply
batteries 4 AA (LR6), NiMH, 1.5V 
lithium or alkaline cells 
(included NiMH, 2500 mAh)
External power supply (USB port) USB mini-B connector on
  • USB port of the computer
  • Power Supply PSA029 with AC voltage
  • USB hub
  • Voltage converter PSA031, 12 V DC  to 5 volts DC
external supply Supply via I / O port: 10.0 to 15.5 V DC
with cable CBL140, CBL154 or interface unit 831-INT
Operating time with 1.5 V lithium > 24 h with saving options (L eq Recording interval with 1 s)
Power consumption with PRM831 1.1 W (without backlight, in the active mode of operation)
memory option
data storage Non-volatile flash memory, backup every minute
Real time clock Stay min. 10 min obtained without batteries


Specific References


831C manual

831C manual (PDF)

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831C brochure (German

831C brochure (German

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831C brochure (PDF)

831C brochure (PDF)

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