Larson Davis SoundAdvisor 831C User manual

Larson Davis
SoundAdvisor
Model 831C
Sound Level Meter
Reference Manual

SoundAdvisor Model 831C i-2
Copyright
Copyright 2020, by PCB Piezotronics, Inc. This manual is copyrighted, with all rights reserved. The manual may not be copied
in whole or in part for any use without prior written consent of PCB Piezotronics, Inc.
Disclaimer
The following paragraph does not apply in any state or country where such statements are not agreeable with local law:
Even though PCB Piezotronics, Inc. has reviewed its documentation, PCB Piezotronics Inc. makes no warranty or representa-
tion, either expressed or implied, with respect to this instrument and documentation, its quality, performance, merchantabil-
ity, or fitness for a particular purpose. This documentation is subject to change without notice, and should not be construed as
a commitment or representation by PCB Piezotronics, Inc.
This publication may contain inaccuracies or typographical errors. PCB Piezotronics, Inc. will periodically update the material
for inclusion in new editions. Changes and improvements to the information described in this manual may be made at any
time.
Safety
If the equipment is used in a manner not specified by Larson Davis, the protection provided by the equipment may be
impaired.
Recycling
PCB Piezotronics, Inc. is an environmentally friendly organization and encourages our customers to be environmentally con-
scious. When this product reaches its end of life, please recycle the product through a local recycling center or return the prod-
uct to:
PCB Piezotronics, Inc.
Attn: Recycling Coordinator
1681 West 820 North
Provo, Utah, USA 84601-1341
where it will be accepted for disposal
Warranty
For warranty information, go to www.larsondavis.com  About Us  Limited Product Warranty.
Contact Larson Davis
Website
www.larsondavis.com
Worldwide Corporate Headquarters
Larson Davis - a PCB Piezotronics division
3425 Walden Avenue
Depew, NY 14043-2495 USA
Toll-free (in the US): 888-258-3222
Phone: [phone]
USA fax: [phone]
E-mail: [e-mail]

I831C.01 Rev N- Firmware Version 4.5
Table of Contents
Module 1 Model 831C Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Module 2 Instrument Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Module 3 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Module 4 Using the Data Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Module 5 Calibrating Your SoundAdvisor 831C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Module 6 Creating a Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Module 7 Making a Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Module 8 Managing Measurement Data Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Module 9 System Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1
Module 10 System Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-1
Module 11 Managing 831C Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11-1
Module 12 System Utilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-1
Module 13 831C Network and Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
Module 14 Upgrading Firmware & Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1
Module 15 Using Measurement History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-1
Module 16 Using Time History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-1
Module 17 Using Event History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17-1

SoundAdvisor Model 831C ii-2
Module 18 Using 831C Sound Recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18-1
Appendix A Technical Specifications ................................................................................A-1
Appendix B Measuring Sound Using IEC 61672-1 .............................................................B-1
Appendix C Glossary ........................................................................................................C-1

SoundAdvisor Model 831C Basic Operations 1-1
Module 1 Model 831C Features
The SoundAdvisor Model 831C SLM is a Class 1 acoustic monitoring
instrument with a full-color touchscreen that measures noise frequency,
sound pressure level, and community and environmental sound. The “C” in
831C refers to the full-color screen.
G4 LD Utility software (G4) connects your meter to your PC via USB, Bluetooth,
WiFi, or TCP/IP. With G4 you can calibrate the meter, create setup files,
download measurements, and analyze the results.
1.1 Basic Operations .................................................................................................................1-1
1.2 Applications .........................................................................................................................1-2
1.3 Hardware Features ..............................................................................................................1-2
1.4 Performance Features .........................................................................................................1-2
1.5 Standard 831C Package Contents ......................................................................................1-3
1.5.1 About Serial Numbers ...........................................................................................1-5
1.6 Available Options and Accessories .....................................................................................1-5
1.6.1 Firmware Options .................................................................................................1-5
1.6.2 Hardware Options .................................................................................................1-6
1.1 Basic Operations
The 831C performs the following operations:
TRY THIS Explore the interface,
press buttons, change settings,
and test the operations.
• Measure all area sound using stop, pause, and resume measurement
• Display broadband and spectral sound values on a full-color display
screen
• View live and stored data while a measurement is in process
• Log simultaneously to time, statistical measurement and event
histories
• Use markers to annotate portions of time histories, including voice
annotation
• Automatically back up data to prevent data loss on power failure
• Calibrate using a Precision Acoustic Calibrator, and store calibration
history
• Time stamping for Lmax, Lmin, Lpeak-(max) single event metrics.
• Sync clock with PC, attached GPS, or Network Time Protocol (NTP)
• Create multiple Setup configurations using the Setup Manager
• Stream and record audio continuously or for events using sample
rates up to 51.2 ksps in compressed or uncompressed format
• Communicate with via USB, Ethernet, cellular, or WiFi
• Operate completely from the device itself, or remotely using G4 LD
Utility software

SoundAdvisor Model 831C Applications 1-2
• Easily expand memory using USB memory
• Automatically synchronize the clock with Network Time Protocol
(NTP) or GPS for optimal accuracy
• Select desired color theme on the full-color graphic LCD display with
touchscreen user interface
1.2 Applications
The 831C monitors:
• City noise
• Construction noise
• Airport noise
• Nuisance noise
• Noise ordinance compliance
• Wind farm noise
1.3 Hardware Features
The 831C is a precision-integrating sound level meter with the following
hardware features:
TAKE NOTE Up to 32GB USB
memory can be purchased from
Larson Davis as an option.
• 2 GB internal industrial grade data memory
• 240 x 320 full-color graphic LCD display with touchscreen user
interface
• Quiet Touch elastomeric keypad
• Meter uses NiMH, photo-lithium, lithium-Ion, and alkaline cells; 4-AA
batteries provide upwards of 8 hours operating time
• AC/DC output jack with full dynamic range option
• Compatible with 61 m (200 ft.) microphone extension cable (full scale
to 20 kHz)
• Dust-resistant, durable plastic case with lanyard (tripod mount is also
available)
• USB 2.0 high-speed host connector for mass storage, weather sensors,
USB headset, and WiFi communication devices
• USB 2.0 high-speed peripheral connector for control and data
download by a PC
• I/O connector for power, weather transducers, logic input/output, and
preamplifier communications
1.4 Performance Features
• Large dynamic range > 120 dBA
• RMS Detectors: Slow, Fast & Impulse
• RMS Frequency Weighting: A, C & Z
• Peak Frequency Weighting: A, C & Z

SoundAdvisor Model 831C Standard 831C Package Contents 1-3
• Any LevelTM Simultaneous measurement and display of Max and Min
sound pressure levels (Slow, Fast and Impulse detectors), plus Leq and
Peak levels, all with A, C and Z frequency weighting
• Weather Measurements (Wind Speed and Direction, Temperature, and
Humidity with SEN03x)
• Multiple language support: English, French, Italian, German, Spanish,
and Chinese
• Field-upgradeable firmware
1.5 Standard 831C Package Contents
The 831C is available as part of a specialized system, or in a standard
configuration. The following accessories come with the standard
configuration:
TAKE NOTE Report any damage or shortage immediately to PCB Piezotronics, Inc. See
“Contact Larson Davis” on page i-2.
The 831C is shipped in protective packaging. First, verify the shipment
contains all parts and accessories for the configuration you selected. Retain
the packaging for safe shipment for calibration service.
Table 1.1 SoundAdvisor 831C Standard Package
Accessory Type Available Items
SoundAdvisor 831C

SoundAdvisor Model 831C Standard 831C Package Contents 1-4
Microphones (377B02) ½-inch free-field
prepolarized microphone, 50
mV/Pa, providing performance
conforming to Class 1 sound
level meter standards
(377C20) ½-inch random
incidence prepolarized
microphone, 50 mV/Pa, providing
performance conforming to Class
1 sound level meter standards
Note: You can use other microphones with the 831C. For more
information, see 1.6.2 Hardware Options for more information.
Microphone
Preamplifiers
PRM831 PRM2103
Accessory Kit
(831-ACC) includes
these items:
(831-CCS) Hard Shell Case
(CBL138) USB to mini-B cable, 1.8 m
4 Rechargeable AA NiMH batteries
(PSA029) Universal AC USB Power
Adapter
(WS001) 3 ½-inch windscreen
Table 1.1 SoundAdvisor 831C Standard Package
Accessory Type Available Items
CAUTION: Sensitive to
static electricity
CAUTION: Sensitive to
static electricity

SoundAdvisor Model 831C Available Options and Accessories 1-5
1.5.1 About Serial Numbers
The 831C serial number is printed on the back panel label. The microphone
model and serial numbers are engraved on the outside of the microphone.
The preamplifier model and serial numbers are engraved on the outside
surface of the preamplifier.
We recommend that you record the purchase date, model and serial numbers
for your instrument, preamplifier, and microphone.
1.6 Available Options and Accessories
In this section:
•1.6.1 Firmware Options
•1.6.2 Hardware Options
1.6.1 Firmware Options
LEARN MORE To purchase these
options, see “Contact Larson
Davis” on page ii-2.
The following upgrades/options are available to purchase from Larson Davis.
831C-LOG
Time History data logging with periods from 2.5 ms to 24 hours.
831C-OB3
Real-time 1/1 & 1/3 Octave Frequency Analysis.
831C-ELA
Measurement History for the manual or timed storage of statistical data, and
exceedance-based Logging Analysis with Events.
•USB Drive includes:
•G4 LD Utility software
•831C Reference Manual
•Digital Calibration Certificates
Lanyard
Table 1.1 SoundAdvisor 831C Standard Package
Accessory Type Available Items

SoundAdvisor Model 831C Available Options and Accessories 1-6
831C-SR
Make event based and manual sound recordings in WAV or OGG format that
can be sent via email or SMS and stored in the measurement data.
831C-MSR
Measurement History for the manual or timed storage of statistical data with
all sound recording capabilities.
831C-SW
Make direct USB communication with Sierra Wireless RV50X cellular gateway.
831C-AUD
Using the AudCal software from Larson Davis in conjunction with your
SoundAdvisor 831C enables you to test the calibration of audiometers and
sound booths.
831C-SCH
Accounts and scheduling feature for G4 LD Utility.
1.6.2 Hardware Options
The following table contains only a few examples of the hardware accessories
available for your 831C. Additional components include, but are not limited
to, microphones, preamplifiers, software, power supplies, tripods, calibrators,
sensors, protective cases, adapters, and cables. For a complete listing of
standard and system accessories, see http://www.larsondavis.com/
products/soundlevelmeters/soundadvisor/soundadvisorordering.
Table 1.2
Accessory Type Available Options
Microphone Options
Note: These mics are available
directly from Larson Davis. You
can also use other
microphones with the 831C.
(377A15) 1-inch, prepolarized
pressure condenser microphone,
50 mV/Pa, providing performance
conforming to Class 1 sound level
meter standards
(377B01) ¼-inch free-field
prepolarized microphone, 50 mV/
Pa, providing performance
conforming to Class 1 sound level
meter standards
(377B10) ¼-inch free-field
prepolarized microphone, 50 mV/
Pa, providing performance
conforming to Class 1 sound level
meter standards
(377C01) ¼-inch free-field
prepolarized microphone, 50 mV/
Pa, providing performance
conforming to Class 1 sound level
meter standards
(377C13)½-inch, prepolarized,
pressure condenser
microphone, 50 mV/Pa,
providing performance
conforming to Class 1 sound
level meter standards
(377C10) ¼-inch free-field
prepolarized microphone, 50 mV/
Pa, providing performance
conforming to Class 1 sound level
meter standards

SoundAdvisor Model 831C Available Options and Accessories 1-7
Microphone Preamplifier
Options
(426E01) 1/2-inch ICP Low Noise
microphone preamplifier (requires
adapter (ADP074)
(PRM2103) Outdoor
microphone preamplifier
Environmental Protection
EPS Environmental Shell
Protects microphone and preamplifier from rain and wind with
mounting options for pipes, poles, and most tripods
EPS030-831
Weather-proof enclosure for remote noise monitoring; includes
battery
NMS/EPS044
Solar-powered noise monitoring system for outdoor, long-term,
and unattended sound monitoring
NMS/EPS045
Permanently-installed, solar-powered noise monitoring system
for outdoor, long-term, and unattended sound monitoring
Weather Data Acquisition
SEN031: combined weather sensor, wind speed and direction
(with no moving parts), temperature, humidity, pressure, and
rainfall (requires CBL170 and DVX008A)
SEN032: Ultrasonic Anemometer: wind speed and direction only sensor
(requires CBL170 and DVX008A).
Communication
DVX012, 013, 014, 015, 008A 831-INT-ET with integrated
Ethernet capability
GPS GPS001 GPS Receiver, USB Magnetic Mount
Equivalent Electrical Impedance Adapter Options
Choose one of the following adapters in place of the microphone when making very high impedance
measurements. The adapter acts as a series capacitor with the same capacitance as the microphone it
replaces. If you’re making a square wave pulse measurement, include a 100 kHz, low pass, T filter with the
adapter.
(ADP002) 6.8pF BNC Input
Adapter for ¼-inch, 7pF
microphone equivalent
(ADP090) 12pF, BNC Input Adapter
for ½-inch, 12pF microphone
equivalent
(ADP092) BNC In-Line, Low
Pass Filter, 75kHz
Table 1.2
Accessory Type Available Options

SoundAdvisor Model 831C Available Options and Accessories 1-8
Table 1.3
Cables: Extension and Interface Cables
Microphone Extension
Cable: EXCXXX (shielded),
where XXX is the length in
feet (XXX = 010, 020, 050,
100 and 200 available)
CBL138 USB Cable CBL139 AC/DC Output Cable

SoundAdvisor Model 831C Assembling Your 831C SLM 2-1
Module 2 Instrument Overview
This module describes the hardware and visual, and display components
that enable the SoundAdvisor Model 831C to perform as a reliable and
diversely competent meter for sound monitoring.
In this module:
2.1 Assembling Your 831C SLM .................................................................................................2-1
2.1.1 Connecting the Microphone and Preamplifier ....................................................2-1
2.1.2 Connecting the Preamplifier to Meter .................................................................2-2
2.1.3 Disconnecting the Preamplifier ...........................................................................2-2
2.1.4 Preparing the 831C for Long Term Storage .........................................................2-3
2.2 Powering the 831C SLM .......................................................................................................2-3
2.2.1 Using Battery Power .............................................................................................2-3
2.2.2 Using External Power ............................................................................................2-6
2.2.3 Understanding 831C Power Events and Indicators .............................................2-7
2.2.4 Powering On or Off ................................................................................................2-8
2.2.5 Using the Power Control Page .............................................................................2-8
2.3 Instrument Hardware Overview .........................................................................................2-9
2.3.1 Using the Keypad ................................................................................................2-10
2.3.2 Navigating and Selecting ....................................................................................2-11
2.3.3 Basic Run Functions ............................................................................................2-11
2.3.4 Entering Text .......................................................................................................2-12
2.4 Display Elements Overview ...............................................................................................2-12
2.4.1 Changing Display Color Themes ........................................................................2-12
2.4.2 Using Tabs and Pages .........................................................................................2-12
2.4.3 About Status Bar Icons and Indicators ..............................................................2-13
2.4.4 Main Menu Overview ...........................................................................................2-16
2.4.5 Tools Menu Overview ..........................................................................................2-17
2.4.6 Power Control Menu Overview ...........................................................................2-18
2.1 Assembling Your 831C SLM
In this section:
•2.1.1 Connecting the Microphone and Preamplifier
•2.1.2 Connecting the Preamplifier to Meter
•2.1.3 Disconnecting the Preamplifier
•2.1.4 Preparing the 831C for Long Term Storage
2.1.1 Connecting the Microphone and Preamplifier
CAUTION DO NOT handle the microphone and preamplifier without observing
the following items:

SoundAdvisor Model 831C Assembling Your 831C SLM 2-2
• Ground yourself so the pogo pin is not exposed to static shock.
• Never use excessive force.
• Gripping tightly or screwing tightly is unnecessary.
• Do not remove the microphone grid cap and expose the diaphragm.
FIGURE 2-1 Microphone and Preamplifier PRM831
The bottom of the microphone attaches to the top of the
preamplifier. The preamplifier body houses a single gold pin with
threads on the top edge, which are designed to fit the 1/2-inch
microphone.
CAUTION Do not allow dust or debris to collect in an unassem-
bled preamplifier.
Step 1 Carefully place the bottom of the microphone over the
top of the preamplifier and gently screw the assembly together.
The microphone body should seat smoothly against the
preamplifier body.
To disconnect the microphone:
• Lightly grip the 2 engraved lines on the microphone body and
gently turn.
2.1.2 Connecting the Preamplifier to Meter
CAUTION Do not attempt to screw the preamplifier onto the 831C.
Step 1 Both the preamplifier and the preamplifier housing on the meter are marked for
correct alignment; look for a vertical, engraved line on the preamplifier, which
aligns with the arrow about the button on the 831C. For reference, see Figure 2-
2.
Step 2 With the alignment marks on both pieces lined up vertically, insert the 5-pin
connector at the bottom of the preamplifier snugly into the top of the 831C
until you hear a small click.
2.1.3 Disconnecting the Preamplifier
FIGURE 2-2 831C Preamplifier Housing
To disconnect the preamplifier, press
and hold this button while gently
pulling the microphone/preamplifier
assembly from the meter.

SoundAdvisor Model 831C Powering the 831C SLM 2-3
2.1.4 Preparing the 831C for Long Term Storage
The Hardware Power Switch on the bottom of the 831C disconnects the
batteries from the 831C hardware (For reference, see Figure 2-4). The real-time
clock maintains its value while the switch is off. The power switch prevents
battery drain when the meter is not in use for an extended period of time. If
you plan to store the meter for more than 2 weeks, remove the batteries.
If the switch is in the “ 0 ” position, the batteries are disconnected. After
installing batteries be sure to move the switch to the “ | ” position.
CAUTION DO NOT use the hardware power switch to turn the 831C OFF. Per-
manent damage and data loss may occur. Press the Power button once, then
select Off.
2.2 Powering the 831C SLM
In this section:
•2.2.1 Using Battery Power
•2.2.2 Using External Power
•2.2.3 Understanding 831C Power Events and Indicators
2.2.1 Using Battery Power
Current Battery Voltage is displayed on the Power Control page. To access the
Power Control page, press the Power button 0.
In the Status Bar section of the meter display, the battery icon indicates the
state of the battery charge by the color and fill.
CAUTION Do not mix different types of batteries. Only charge NiMH batteries.
CAUTION Do not mix batteries from different manufacturers, replace all 4 bat-
teries at the same time.
CAUTION When changing batteries, select the correct Battery Type in System
Properties. See 9.4.1 Changing Batteries and Editing the Battery Type.
CAUTION Resolve a Session Log entry “Charging Stopped” by checking the
batteries, and ensuring the correct battery type is selected in System Proper-
ties. Additionally, the battery may be too old to charge. Battery may also be
Full Charge Low Charge

SoundAdvisor Model 831C Powering the 831C SLM 2-4
read as an incorrect battery type, which may happen to fully discharged NiMH
batteries. Use an external battery charger to restore charge, then install in
meter. Additionally, the batteries may be too hot or too cold.
CAUTION The 831C is compatible with Energizer, Duracell, and other commer-
cially-recognized brands of these battery types:
• AA nickel metal hydride (NiMH)
• AA Alkaline
• AA 1.5 Volt Lithium
CAUTION Optimal battery temperature is 0° C–45° C.
Understanding the Low Battery Indicator
As the battery nears the end of expected life, the empty battery symbol begins
to flash. When the battery is no longer functioning, the 831C stops running,
saves all data and instrument status, then turns off. When you power the 831C
is again with fresh batteries or an external power supply, the unit returns to
the state it was in prior to shutting down.

SoundAdvisor Model 831C Powering the 831C SLM 2-5
Installing Batteries
The battery compartment of the 831C is on the back of the instrument. When
installing batteries, always insert 4 fresh AA batteries, and observe polarity
markings as shown here.
Charging Batteries in the 831C
Before you begin:
• Install batteries as shown in "Installing Batteries" on page 2-5.
You can charge batteries (NiMH only) in the meter in about 7 hours when the
meter is turned OFF.
Step 1 On the 831C, press Tools 3  System Properties.
Step 2 Select NiMH as the Battery Type.
Step 3 The Charge drop-down menu is automatically set to On. If you do not want your
power source to charge the batteries, select Off.

SoundAdvisor Model 831C Powering the 831C SLM 2-6
Step 4 Select Save, then click Yes to confirm your choice.
TAKE NOTE Batteries charge more efficiently when the meter is powered off. For details
about 831C button LED indicators, see “Understanding Charging Status LED
Indicators” on page 2-6.
Step 5 Power the meter OFF.
Step 6 Connect the meter (with the USB cable) to the included power cable (PSA029),
and plug this in to a wall outlet or other external power source.
TAKE NOTE If you’re using a power cable other than the one supplied with the meter, use
a 28 AWG or larger wire for proper charging.
Understanding Charging Status LED Indicators
The charge status indicated by the green LED behind the Power button is as
follows:
• Solid green: Charging
• No green light: Not charging
• Green light wink: Maintaining charge
• Green light fast blink (two times per second): Charger fault
• Green light fastest blink (three times per second): Meter is powering
up or shutting down
Resolving a “Charging Stopped” Session Log Entry
To resolve a “Charging Stopped” Session Log entry, check the battery
placement, and make sure the correct Battery Type is selected (Tools 
System Properties).
Resolving an “Incorrect Battery Type” Session Log Entry
Infrequently, when the battery becomes too old to charge, the meter may
register the battery as the incorrect battery type. This can also occur when
newer NiMH batteries are fully discharged. In this case, charge the batteries
using an external battery charger, then install them in the meter.
You may also see this error when the batteries become too hot or too cold.
Optimal battery temperature is 0° C–45° C.
2.2.2 Using External Power
We recommend maintaining the internal battery The 831C utilizes the
following external power sources:
• USB port from a computer
• USB port from PSA029 power supply
• I/O connector from an external +10.8 to +25 Volt DC mains power
source.

SoundAdvisor Model 831C Powering the 831C SLM 2-7
Using USB Port Power
The 831C can be powered via the mini-USB Type B port with the PSA029
external power supply and the included power cable (CBL138). The mini-USB
Type B connector is located on the bottom of the meter.
CAUTION If you operate the 831C without batteries and power is interrupted,
you may loose your data.
With the PSA029 power supply connected and operating at rated conditions,
the 831C operates properly with or without batteries installed. Use the
included cable to prevent excessive power loss.
2.2.3 Understanding 831C Power Events and Indicators
Understanding a Low Voltage Shutdown Event
The 831C preserves the service life of an external battery by preventing it from
being discharged excessively. When the battery voltage drops below the
External Shutoff Voltage (default value +10.8 volts) and remains above +10.2
volts for one minute, the instrument stops, saves data, and turns off.
Understanding a Power On After Power Loss Event
When the 831C is powered from an external supply and the input voltage falls
below the indicated External Shutoff Voltage threshold, it powers off. When
the 831C shuts down due to a low battery, it automatically attempts to power
up after a short reprieve. If there’s adequate power, it remains on. However, if
the battery is still discharged, it powers off. This attempted “power on” cycle
continues until the meter has sufficient power to remain on. This feature is
designed to allow the 831C to automatically restart when power is lost due to
low solar situation or after an extended power outage.
LEARN MORE To learn more about reboot time after a power loss, see “Low Power At
Boot-Up” on page A-6.
Understanding a Sudden Loss of External Voltage Event
When the external voltage is suddenly lost—if the external supply is
disconnected or the main power fails and there is no external battery—the
831C continues to run on internal batteries if they are present and in good
condition. If battery power is not present, the 831C immediately switches to
an internal recovery battery and powers down safely.
Understanding the External Power Indicator
When connected to an external power source using the included USB cable,
the External Power icon replaces the Battery icon.
If your meter has fully-charged NiMH batteries and is plugged into a power
source, this icon indicates that it’s using power from the external source, and
is not charging or using any power from the batteries.

SoundAdvisor Model 831C Powering the 831C SLM 2-8
Understanding a Low Power At Boot-Up Event
At start up, the 831C performs a power check. If the supplied power is too low,
the low power icon displays over top of the first display. For more
information see Table A.3, “Low Power At Boot-Up”.
2.2.4 Powering On or Off
Powering On
Press and hold the ON/OFF button 0 on the meter until the screen flashes
and the green LED under the button turns on.
Powering Off
There are 3 ways to power off the 831C:
1. Press the ON/OFF button 0 once to access the Power Control page, then
press the top-left softkey to select Off.
2. From any screen, press and hold the ON/OFF button 0 for 3 seconds to
begin the shut down sequence.
3. Press and hold the ON/OFF button 0 for 10 seconds to force an
immediate shutdown. CAUTION: Using this method may result in lost data.
2.2.5 Using the Power Control Page
From the Live View, press the UP button 8 to view your meter’s current
power settings (Live 8/8).
Battery settings display
here. You can edit these
settings from the Power
Control page. For more
information, see 9.4
Editing Power Settings.