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

basic data
Averaging (integration method)Linear or exponential
RMS-term reviewSlow, fast or pulse
frequencyA, C or Z
Peak FrequencyA, C or Z
reinforcement0 dB or +20 dB
doubling rates3, 4, 5 or 6 dB with option 831-IH
sampling rate51,200 Hz
Rise time (peak value)
reference level114.0 dB re. 20 uPA
Reference level rangeOne big area for SLM Normal Option OBA, Gain 0 dB
reference frequency1000 Hz
reference direction0 ° 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 microphone12 pF for 1/2 "microphone Larson Davis
Field level error (option OBA)≤± 0.1 dB relative to the reference region
Refresh rate of the screenFour 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 cordNo effect (up to 61 m with EXCxxx cable)
Electrostatic dischargesThe device is not adversely affected by electrostatic discharge.
Extended weather options-40 ... +70 ° C with CE-831-E
level0.1 dB
Elapsed time0.1 s
Real Time Clock1 s
calendarUntil December 31, 2100
integration time
Time-averaged values ??and sound exposure level (s)
   minimum0.1 s
   Maximum active daily 
   Maximum daily with inactive 
> 23 days with <0.5 dB error
Dosimeter measurements: TWA, noise dose (s)
   minimum0.1 s
In statistics
Number of selectable parameters6 in the format xx, xx%, visible on the model 831c
Storing the complete table0.1 dB steps
Spectral statisticsRequires octave analysis option (831c-OB3)
Number of markers10
already numbered with names marker5: truck, passenger car, motorcycle, plane, exclusion (of the measurement)
Backward-delete function
Backward erase time5 or 10 seconds
Supported modesManually
Control modes for the measurement
existing modesManual stop, timed stop, stop if stable, continuous, single-block timing, daily block timing
Timed stopTime in hh: mm: ss
Stop if stableLevel difference in xx.x dB and time in hh: mm: ss
Continuously with daily automatic storage1, 2, 4, 6, 12, 24, 48, 96 or 144 files per day, automated file number 'yymmddnn.LD0'
Continuous restart after power failureAutomatically at 12 V DC
Single block timingStart: date and time; End: date and time
Day Block TimingUp 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 recordsWith headset (ACC003) or measuring microphone
Sampling rate of the recording8 ksps
monitoring optionsModel 831c or processing software for .wav files
AC / DC output
Rifle2.5 mm, for cable CBL139
AC output - voltage range± 2.3 V pk  maximum 0.5 ... 1.6 V mV rms  sinusoidal
AC output - Recommended loadheadset; Speaker impedance> 16 ?
DC output - voltage scale10 mV per dB, 100 dB for 1 V
DC output - frequency and timeCorrespond to the SLM settings: A, C or Z and S, F or I
Signal tap the preamplifierWith ADP015 and EXC006
power supply
batteries4 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 supplySupply 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 PRM8311.1 W (without backlight, in the active mode of operation)
memory option
data storageNon-volatile flash memory, backup every minute
Real time clockStay min. 10 min obtained without batteries

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