Larson Davis 831 User Manual

Model 831

Sound Level Meter

Manual

Larson Davis

Model 831 Manual

I831.01 Rev O Manual

Copyright

Copyright 2016, 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 representation, either expressed or implied, with respect to this instrument and
documentation, its quality, performance, merchantability, 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.

Record of Serial Number and Purchase Date

Model 831 Serial Number: ___________
Preamplifier Model: _________ Serial Number: ___________
Microphone Model: _________ Serial Number: ___________

Recycling

PCB Piezotronics, Inc. is an environmentally friendly organization and encourages our customers to

be environmentally conscious. When this product reaches its end of life, please recycle the product
through a local recycling center or return the product 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, refer to our Terms and Conditions of Sale on our website,

www.larsondavis.com/TermsConditions.aspx.

Table of Contents

Chapter 1 831 Features 1-1

Hardware Features ................................. .................................. ............................. 1-1

Basic Measurements ............................................................................................. 1-2

Basic Operation ..................................................................................................... 1-2

Available Options ............................................. .................................................... 1-3

Standard Accessories ............................................................................................ 1-4

Optional Accessories ............................................................................................. 1-5

Chapter 2 First Use 2-1

Unpacking and Inspection ..................................................................................... 2-1

Connecting the Microphone and Preamplifier ...................................................... 2-2

Connecting the Preamplifier ................................................................................. 2-3

Disconnecting the Preamplifier ........................................................... .................. 2-4

Powering the Model 831 ....................................................................................... 2-4

Chapter 3 Overview 3-1

831 Components ................................................................................................... 3-1

Summary of Displays and Icons ........................................................................... 3-7

Navigating and Selecting ....................................................................................3-12

Basic Run Functions ...........................................................................................3-12

Tab and Setting Displays .................................................................................... 3-13

Parameter Selection ............................................................................................. 3-20

Chapter 4 Basic Measurement Setup 4-1

Settings Screen ...................................................................................................... 4-1

Setup Tabs .................................................................................................... ......... 4-2

Exiting Settings Screen ....................................................................................... 4-15

Setup Manager ................................. .................................. .................................4-16

Chapter 5 Data Display 5-1

Data Labels ........................................................................... ... ............................. 5-1

Tabbed Structure ............................................................................................... .... 5-1

Live Tab ...................................... .................................. ........................................ 5-2

Overall Tab ............................................... .......................................................... 5-12

C-A and Impulsivity ............................................................................................ 5-23

Session Log Tab ..................................................................................................5-25

Adjust Graph Scale ............................................................................................. 5-29

I831.01 Rev O Manual

View Spectrum Normalized ................................................................................5-30

Any Level Display ...............................................................................................5-41

Chapter 6 Run Control 6-1

Run Control Setup .................................................................................................6-1

Run Mode with Measurement History ..................................................................6-3

Run Modes Without Measurement History ...........................................................6-4

Chapter 7 Making a Measurement 7-1

Configuration of the System ..................................................................................7-1

Switching On the Model 831 ................................................................................. 7-1

Model 831 Setup ....................................................................................................7-3

Calibrating the Model 831 .....................................................................................7-3

Positioning the Model 831 .................................................................... .................7-3

Performing the Measurement ................................................................................7-5

Storing the Measurement .....................................................................................7-15

Recovery After Improper Shutdown ...................................................................7-17

Chapter 8 Calibration 8-1

Calibration Overview .............................................................................................8-1

Control Panel - Calibrate .......................................................................................8-2

Acoustic Calibration ..............................................................................................8-5

Sensitivity Tab .....................................................................................................8-13

Calibration Without Preamplifier ........................................................................8-15

Certification ......................................................................................................... 8-16

E.A. Check .......................................................... .................................. ...............8-18

E.A. History ................................................... ......................................................8-20

Chapter 9 Industrial Hygiene 9-1

Measurement Setup ...............................................................................................9-1

Data Display ..........................................................................................................9-5

Chapter 10 Voice Recording 10-1

Control Panel - Voice Recording .........................................................................10-1

Voice Recorder ....................................................................................................10-2

Chapter 11 Time History 11-1

Metrics Logged ....................................................................................................11-1

Time History Setup ..............................................................................................11-4

Time History Display ..........................................................................................11-9

Locate Record Number ..................................................................................... 11-16

Link to Measurement History Display .............................................................. 11-17

Markers ............................................................................................................. 11-18

Chapter 12 Measurement History 12-1

Run Control with Measurement History ............................................................. 12-1

Continuous and Timer Modes ............................................................................. 12-2

Timed Stop Mode ................................................................................................ 12-3

Manual and Stop When Stable Modes ................................................................ 12-5

Display of Measurement History Data ................................................................12-5

Storing a Measurement History ........................................................................12-11

Link to Time History ......................................................................................... 12-11

Chapter 13 Event History 13-1

Level Based Events ............................................................................................. 13-1

Event History Setup ....................... .....................................................................13-2

Trigger Method ................................................................................................... 13-3

Event Time History Setup ................................................................................. 13-10

Event History Display .......................................................................................13-12

Link to Time History and Measurement History .............................................. 13-22

Chapter 14 FFT and Tonality 14-1

Accessing FFT Mode .......................................................................................... 14-1

Configuring a Measurement ............................................ ... .................................14-3

Viewing and Analyzing Results ........................................................................ 14-10

Storing Data ................................ .................................. ....................................14-21

Viewing Stored Data ......................................................................................... 14-21

Return to Sound Level Meter Mode ......................................................... ........ 14-22

Chapter 15 RT-60 15-1

Accessing RT-60 Mode ............................................. ......................................... 15-1

Making a Measurement .......................................................................................15-3

Viewing and Analyzing Results .......................................................................... 15-8

Manually Controlling the Internal Noise Source .............................................. 15-16

Customizing Measurements ............................................ ..................................15-20

Storing Data ................................ .................................. ....................................15-26

Viewing Stored Data ......................................................................................... 15-26

Quality Indicators .............................................................................................. 15-27

Accuracy Grade ................................................................................................. 15-28

Return to Sound Level Meter Mode ......................................................... ........ 15-29

I831.01 Rev O Manual

Chapter 16 Sound Recording 16-1

Sound Recording Types ....................................................................................... 1 6-1

Sound Recording Setup .......................................................................................16-2

Manual Sound Recording ....................................................................................16-7

Marker Initiated Recording .................................... ..............................................16-9

Event Sound Recording .....................................................................................16-14

Measurement History Sound Recording ............................................................16-18

Combined Sound Recordings ............................................................................16-19

Sound Recording Playback ................................................................................16-20

Chapter 17 Data Explorer 17-1

Control Panel - Data Explorer .............................................................................17-1

Data Explorer .......................................................................................................17-2

Chapter 18 System Properties 18-1

Control Panel - System Properties .......................................................................18-1

Device ..................................................................................................................18-2

Time .....................................................................................................................18-3

Power ...................................................................................................................18-5

Preferences ......................................................................................................... 18-10

Localization .......................................................................................................18-20

Displays .............................................................................................................18-23

Options ...............................................................................................................18-29

Logic I/O ............................................................................................................18-31

Chapter 19 Non-Acoustical Inputs 19-1

831-INT ...............................................................................................................19-1

Weather Measurement Using 831-INT ...............................................................19-2

Location Measurement Using 831-INT .............................................................19-10

Chapter 20 Communication 20-1

Control Panel - Communication ..........................................................................20-1

Modem Tab ..........................................................................................................20-3

Wireless Tab ........................................................................................................20-6

RS-232 Tab ...................................................................................................... ....20-8

SMS Out ..................................................... .......................................................20-12

Network Tab ......................................................................................................20-13

Status Tab ..........................................................................................................20-15

Troubleshooting .................................................................................................20-20

Chapter 21 Lock/Unlock the Model 831 21-1

Control Panel - Lock ...........................................................................................21-1

Fully Locked ....................................................................................................... 21-5

Locked With Auto-Store ............................................... ...................................... 21-6

Locked With Manual-Store ................................................................................. 21-7

Calibration When The Model 831 Is Locked ...................................................... 21-8

Chapter 22 About 22-1

Control Panel - About ......................................................................................... 22-1

About ................................................................................................................... 22-1

Standards ............................................................................................................. 22-2

Options ................................................................................................................ 22-3

User ..................................................................................................................... 22-4

Chapter 23 System Utilities 23-1

Control Panel - System Utilities ..........................................................................23-1

File System .......................................................................................................... 23-2

Chapter 24 Parameters Measured 24-1

Basic Sound Level Measurements ...................................................................... 24-1

Sound Exposure Metrics Measured .................................................................... 24-3

Statistical Metrics Measured ............................................................................... 24-4

Exceedance Counters .......................................................................................... 24-6

Miscellaneous Parameters ................................. .................................................. 24-6

Time History (831-LOG Required) .................................................................... 24-6

Measurement History (831-ELA Required) ....................................................... 24-6

Event History (831-ELA Required) .................................................................... 24-6

Chapter 25 Memory Utilization 25-1

Out Of Memory Stop .......................................................................................... 25-1

Overall Data ..................................... .................................. .................................25-1

Session Log ......................................................................................................... 25-1

Measurement History .......................................................................................... 25-2

Time History ....................................................................................................... 25-2

Events .................................................................................................................. 25-2

Voice Messages ...................................................................................................25-3

Sound Recording .................................................................................................25-3

Bad Flash Blocks ........................................................................... ..................... 25-4

I831.01 Rev O Manual

Chapter 26 Upgrade Firmware and Options 26-1

SLM Utility-G3 ...................................................................................................26-1

Upgrading Model 831 Firmware .........................................................................26-2

Upgrading Options ..............................................................................................2 6-7

Appendix A Technical Specifications A-1

Standards Met by Model 831 ............................................... .................................A-1

Model 831 Specifications .....................................................................................A-2

CE Information ...................................................................................................A-20

1/1 and 1/3 Octave Filters ...................................................................................A-21

Position of Instrument and Operator ...................................................................A-30

Frequency Response ...........................................................................................A-32

Vibration Sensitivity ...........................................................................................A-62

Appendix B Measuring to IEC61672-1 B-1

Sections 5, 6, 7 and 9 (except 9.3) ........................................................................B-1

Appendix C Integrated Level Calculations C-1

Basic Integrated Level Calculations .....................................................................C-1

Community Noise Descriptors .................................... .........................................C-9

Appendix D Glossary D-1

CHAPTER

1

Hardware Features

831 Features

Welcome to the Larson Davis Model 831. This versatile
instrument, with graphic display, performs the functions of
several instruments; It puts the combined features of a
precision sound level meter and a real-time frequency
analyzer in the palm of your hand.

The Larson Davis Model 831 has the following features:

• Precision integrating sound level meter

• 2 GB data storage

• 160 X 240 graphic LCD display with backlight and
icon-driven user interface

• Quiet Touch elastomeric keypad

• Large dynamic range > 120 dBA

• RMS Detectors: Slow, Fast & Impulse

• RMS Frequency W e ightin g: A, C & Z

• Peak Frequency Weighting: A, C & Z

• Any Level
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)

• Jack for AC/DC output or headset microphone and
speaker

• Compatible with 61 m (200 ft.) microphone extension
cable (full scale to 20 kHz)

• 4-AA batteries provide upwards 8 hour operating
time

• Dust tight (IP53) durable plastic case with tripod
mount (tripod not included) and lanyard

TM

: Simultaneous measurement and display

Model 831 Manual 831 Features 1-1

Basic Measurements

Basic Operation

• USB 2.0 full speed host connector for mass storage,
cellular and dial-up modems and future devices

• USB 2.0 full speed peripheral connector for control
and data download by a PC

• AUX control connector for USB remote power,
weather transducers and the 831-INT

• I/O connector for communicating with peripheral
devices such as weather transducers

• Multiple language support: English, French, Italian,
German, Spanish and Russian

• Field-upgradeable firmware

• SPL, Leq, Lmax, Lmin, Lpeak, Lpeak(max)

• 2 RMS event counters and 3 Peak event counters

•L

statistics: computed to 0.01% with 0.1 dB

N

accuracy over the range L
display of six on the meter, and Histogram tables

through L

0.01

99.99

, with

• Status Bar and About display

• Auto-Store with Auto-Reset

• Run Timer and Stop-When-Stable Control

• Back-erase

• Markers to annotate portions of time histories

• Real-time clock

• Start time, elapsed time and paused time

• Time stamping for Lmax, Lmin, Lpeak(max) metrics

• Session Log

• Lock functions

• Calibration with calibration history and list of
calibrators

• Power management

• Status bar and About display

• Names Setup files and Setup Manager

1-2 Basic Measurements Model 831 Manual

Available Options

Purchase Required Options

• Data files and Data Explorer

• Automatic data backup to prevent data loss on power
failure

• Overall measurement

• Community Noise Measurement

• V oice Annotation

•GPS Data

The Model 831 is delivered with all firmware options
available at the time of manufacture already installed.
However, only those options which have been purchased
have been enabled. Any of the other firmware options can be
enabled at a later date, following purchase, using a file
delivered from Larson Davis via the Internet.

• Real-time 1/1 & 1/3 Octave Frequency Analysis
(831-OB3)

• Measurement History for the manual or timed
storage of statistical data (831-ELA)

• Automatic Data Logging with periods from 20 ms to
24 hour (831-LOG)

• Fast Spectral Time History Data Logging with
intervals of 2.5, 5.0 or 10 ms (831-FST, requires 831­LOG and 831-OB3)

• Exceedance-based Logging Analysis with Events
(831-ELA). Automatic sound recordings can also be
made when the 831-SR option is also enabled

• Industrial Hygiene Measurement (831-IH)

• Sound Recording (831-SR)

• Advanced IP Communication for Cellular
connectivity (831-COMM)

• RT60 (831-RT): Instrument mode for measuring
reverberation time

• FFT (831-FFT): FFT Instrument mode

Model 831 Manual Available Options 1-3

No Charge Options

Standard Accessories

The following options are available at no additional charge:

• Weather Data: Wind Speed and Direction,
Temperature, Humidity (831-WTHR)

• Analog Modem or RS-232 Communication
(831-MDM)

Some of these options may not be
provided with systems designed for
specific applications.

Microphone Preamplifier

Microphone

Software CD

Accessory Kit

The Model 831 is generally delivered with the standard
accessories described below.

• PRM831 (16 to 140 dB measurement range)

• PRM2103 (16 to 140 dB measurement range)

• 377B02 1/2” free-field pre-polarized microphone,
50 mV/Pa, providing performance conforming to
Class 1 sound level meter standards

or

• 377C20 1/2” random incidence pre-polarized
microphone, 50 mV/Pa, providing performance
conforming to Class 1 sound level meter standards

• G4 LD Utility Software for setup, measurement,
download, and data viewing through CBL138 USB,
TCP/IP, serial, or analog modem connections

• SL M Util ity-G 3 soft ware fo r setup , cont rol and high
speed data download, for which a CBL138 USB cable
is required to utilize the software

Included with purchase of 831-FF or
831-RI; not included when Model
831 is purchased without
microphone and preamplifier.

1-4 Standard Accessories Model 831 Manual

831-ACC including:

• 831-CCS Hard Shell Case

• PSA029 Universal AC Power Adaptor, providing
power from PC via USB port

• CBL138 USB to mini-B cable, 1.8 m

Other

Optional Accessories

Microphones

Microphone Preamplifiers

Environmental Protection

• WS001 3 1/2” Windscreen

• 4 Rechargeable AA NiMH batteries

• Lanyard

• 1/2” free-field pre-polarized microphone, 50 mV/Pa

• 1/2” random incidence pre-polarized microphone,
50 mV/Pa

• 1/4” free-field pre-polarized microphone, 4 mV/Pa,
for higher level and/or higher frequency
measurements (ADP043 adaptor required)

• 1/4” pressure pre-polarized microphone, 1.6 mV/Pa,
for higher level and/or higher frequency
measurements (ADP043 adaptor required)

• 1/2” ICP Low Noise Microphone Preamplifier
(requires adaptor ADP074)

• PRM2103 Outdoor Microphone Preamplifier

• PRM426A12 Outdoor Microphone Preamplifier

• 426A12-NPT Coupler, 1.5”X27”ISO228-1 to NPT
thread

• EPS2116 Environmental Shell, protects microphone
and preamplifier from rain and wind with mounting
options for pipes, poles, and most tripods

• EPS2106-2 Environmental Shell, protects
microphone and preamplifier from rain and wind
and used with tripod TRP003

• EPS2108-2 Environmental Shell, protects
microphone and preamplifier from rain and wind
and used with tripod TRP002

• EPS029-831 Weather-proof enclosure for remote
noise monitoring; includes two batteries and
microphone mast

Model 831 Manual Optional Accessories 1-5

• EPS030-831 Weather-proof enclosure for remote
noise monitoring; includes battery

• EPS031 Pole mount weather proof fiberglass
enclosure for AC power and mounting to TRO019­XX and TRP020-XX series tripods; includes
enclosure, internal brackets and 9-AH backup
battery

• EPS032 Pole mount weather proof fiberglass
enclosure for solar power and mounting to TRP019­XX and TRP020-XX series tripods; includes
enclosure, internal brackets and solar charger

• EPS033 Steel security band for NMS systems

• NMS016 Permanent noise monitoring system with
weather proof enclosure and tilt down pole designed
for AC power; includes Model 831, EPS031, 831-INT,
17' pole, 426A12, 9-AH backup battery and fiberglass
enclosure

• NMS017 Permanent noise monitoring system with
weather proof enclosure and tilt down pole designed
for solar power.; includes Model 831, EPS032, 831­INT, 17’ pole, 425A12, solar charger and fiberglass
enclosure, with the following optional solar
accessories available:

•PSA012-80 80W SOLAR PANEL

•PSA012-50 50W SOLAR PANEL

•BAT012 100AH BATTERY

• NMS018 Portable Noise monitoring system with
weather proof enclosure and tripod designed for AC
power; includes Model 831, EPS031, 831-INT, heavy
duty tripod (10’, 15’ and 20’ configurable heights),
426A12, 9-AH back up battery and fiberglass
enclosure

• NMS019 Permanent noise monitoring system with
weather proof enclosure and tripod system designed
for solar power; includes Model 831, EPS032, 831­INT, heavy duty tripod (10’, 15’ and 20’ configurable
heights), 426A12, solar charger and fiberglass
enclosure, with the following optional solar
accessories available:

•PSA012-80 80W Solar Panel

•PSA012-50 50W Solar Panel

1-6 Optional Accessories Model 831 Manual

Weather Data Acquisition

•BAT012 100AH Battery

•BAT013 2X21AH batteries

• 831-INT 831 Interface Unit for use with 426A12
Outdoor Microphone Preamplifier and weather
sensors

The SEN028, SEN029, and SEN030
are no longer supported.

Communication DVX008A

GPS

Equivalent Electrical Impedance Adaptor

• SEN028 Wind Monitor; Speed and Direction

• SEN029 Anemometer; Speed and Direction
(Low Cost)

• SEN030 Sensor; Temperature and Humidity

• SEN031 Sensor; Weather Station

• MDMUSB-A Modem V.90 Dial-up with USB
Interface

• MDMUSB-E Modem Edge USB Wireless Quad-Band
GSM

• DVX008A USB to RS232, 9 Pin Adaptor

• CBL117 Serial Null Modem Cable, Connects
DVX008A to PC Serial Port

• 831-INT-ET 831-INT with integrated Ethernet
capability

• GPS001 GPS Receiver, USB Magnetic Mount

An equivalent electrical impedance adapter can be used in
place of the microphone when very high impedance
measurements need to be made and the instrument is b eing
tested electrically. The adapter is simply a series capacitor
with the same capacitance as the microphone it is replacing.
The following adapters will be available for sale. If square
wave pulse measurement is to be performed, then the
adapter must also be used with a 100 kHz, low pass, T filter.

• ADP002 6.8pF BNC Input Adaptor for 1/4 in., 7pF
microphone equivalent

• ADP090 12pF BNC Input Adaptor for 1/2 in., 12pF
microphone equivalent

• ADP092 BNC In-Line Low Pass Filter 75kHz

Model 831 Manual Optional Accessories 1-7

Cables

Power Supply

Direct Input Cable or Adaptor

• 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

Cables for Environmental Monitoring

• CBL152 Cable; 426A12 to 831 Signal, 20’

• CBL153 Cable; 426A12 to 831-INT Control, 20’

• CBL154 Cable; 426A12 to Model 831 Control, 20’

• CBL144 Cable; PRM2100 to 831 Signal, 20’

• CBL145 Cable; PRM2100 to 831 Control, 20’

• CBL146 Cable; PRM2100 to 831-INT Control, 20’

• CBL203 Cable; PRM2103 to 831Control, 20’

• CBL208 Cable; PRM2103 to 831-INT Control, 20’

Cable for use with PSA027 Universal Input Power
Supply AC Power Adaptor

• CBL140 Cable; 831 Power, 2.5 mm JACK, 1’

• PSA027 Universal 90-240 AC Power Adaptor
providing power from electrical outlet, used to power
the Model 831 in conjunction with CBL140, CBL145
or CBL154. 1.25 A, 2.5X5.5X14 mm

• BAT015 External battery powering device for the
831, holding 4 or 8 D-sized alkaline 1.5 volt batteries
to extend run time

1-8 Optional Accessories Model 831 Manual

Tripods

• TRP001 Instrument/Camera Tripod with ADP032
1/2 in. microphone clip and used with EPS2108-2

• TRP002 Microphone Stand with Boom

• TRP003 Support Tripod, heavy duty, can be used
with EPS029, EPS030 and EPS2106-2

• ADP034 Mounting adapter to attach EPS2106-2 to
TRP003

• ADP091 Mounting adapter, 426A12 TO TRP003

• TRP019 Permanent 17' tilt down pole. Use with
EPS031 AND EPS032

The TRP020-06 tripod is not for use
with EPS031 AND EPS032.

Other Hardware

• TRP020-06 Heavy duty 6' tripod. Use with 426A12,
EPS030-831 AND EPS029-831

• TRP020-10 Heavy duty 10' tripod. Use with 42 6A12,
EPS030-831, EPS029-831, EPS031 and EPS032

• TRP020-15 Heavy duty 15' tripod. Use with 42 6A12,
EPS030-831, EPS029-831, EPS031 and EPS032

• TRP020-20 Heavy duty 20' tripod. Use with 42 6A12,
EPS030-831, EPS029-831, EPS031 and EPS032

• ACC003 Headset with microphone for voice
recording/playback

Calibrators

• CAL200 Class 1 Sound Level Calibrator, 94/
114 dB @ 1 kHz

• CAL250 Class 1 Sound Level Calibrator,
114 dB @ 250 Hz

Soft Case

• CCS032 pouch with belt clip

Model 831 Manual Optional Accessories 1-9

Software

• DNA (Data Navigation and Analysis) software
provides setup and remote operation of the Model
831, providing real-time data displays on a PC.
Powerful graphics routines are provided to create
custom data displays ranging from simple time
histories and frequency spectra to spectrograms (level
vs frequency vs time) and annotated data
presentations. A variety of advanced post-processing
tools can be used to extend measured data to
engineering results such as searching time history
data for user-defined events, masking or modifying
portions of measured data and recalculating Leq and
searching spectra for pure tones. DNA will take you
from measured data to a completed project, including
report generation.

1-10 Optional Accessories Model 831 Manual

CHAPTER

First Use

2

This chapter outlines the steps to unpack the Model 831 and
prepare it for first use. The following topics are covered:

• Unpacking and Inspection

• Connecting the microphone and preamplifier

• Installing 4 AA batteries

• Using USB power

• Powering-up the Model 831

You will then be ready to use the Model 831 for actual
measurements.

Unpacking and Inspection

Your Model 831 has been shipped in protective packaging.
Please verify that the package contains the items listed
below. Retain the packaging for safe shipment for
calibration service. Report any damage or shortage
immediately to PCB Piezotronics, Inc. at [phone]
(toll free) or [phone].

• Model 831

• PRM831 Microphone Preamplifier

•Microphone

Included with 831-FF and 831-RI.
Not included when 831 is purchased
without preamplifier and
microphone.

Model 831 Manual First Use 2-1

• 831-ACC including

•831-CCS Hard Shell Case

•PSA029 Universal AC Power Adaptor

•WS001 3 1/2” Windscreen

• Lanyard

• 4 - AA NiMH batteries

If you have not already done so, please record the purchase
date, the model and serial numbers for your instrument,
preamplifier and microphone in the spaces provided on the
copyright page “Record of Serial Number and Purchase
Date” on page 2-ii. You will find the instrument’ s Model and
Serial numbers printed on the label on the instrument’s back
panel. The microphone model and serial numbers are

engraved on the outside of the microphone as shown in
FIGURE 2-1 "Microphone" . The preamplifier model and
serial numbers are engraved on the outside surface of the
preamplifier. You may be asked to provide this information
during any future communications with PCB Piezotronics,
Inc.

FIGURE 2-1 Microphone

Connecting the Microphone and Preamplifier

The bottom end of the microphone attaches to the top end of
the preamplifier. The top end of the preamplifier has a single
gold pin and threads on the preamplifier body. The model
and serial number of the microphone are engraved on the
side.

FIGURE 2-2 Microphone-Preamplifier

Carefully place the bottom end of the microphone over the
top end of the preamplifier and gently screw the assembly
together. The microphone body will seat smoothly against
the preamplifier body. DO NOT use excessive force.

When removing the microphone, turn while gripping the
microphone body, not the grid cap, to prevent damage to the
microphone diaphragm.

2-2 Connecting the Microphone and Preamplifier Model 831 Manual

Connecting the Preamplifier

Caution: Do not attempt to unscrew
the collar/ring at the top of the
Model 831 body.

The bottom end of the preamplifier has a 5 pin connector
that fits snugly into the top of the Model 831. Insert the
preamplifier into the mating connector on the Model 831.
The connectors are keyed for correct alignment; there is a
laser engraved line on the preamplifier which aligns with the
arrow on the Model 831. Rotate the preamplifier until the
keyways line up. Press the assemblies together until a small
click is heard. The microphone / preamplifi e r a ssemb ly is
now securely attached to the Model 831.

If the Model 831 is ON when the preamplifier is connected
to the Model 831, the Preamp Connected message box will
appear for several seconds.

FIGURE 2-3 Preamplifier Connected

5 to clear the message box.

Press

Model 831 Manual Connecting the Preamplifier 2-3

Disconnecting the Preamplifier

Preamplifier Release

On the front surface of the Model 831, just below the
preamplifier connector, is a small button. Press and hold this
button while pulling the microphone / preamplifier assembly
out of the Model 831.

FIGURE 2-4 Push Button to Release Preamplifier

If the Model 831 is ON when the preamplifier is
disconnected, the Preamp Disconnected message box will
appear for several seconds.

Powering the Model 831

2-4 Disconnecting the Preamplifier Model 831 Manual

FIGURE 2-5 Disconnect The Preamplifier

5 clear the message box.

Press

The following section provides power information for the
model 831, including the following:

• Battery Power

• External Power Supply

• Power Up Operation

• Power Control Page

• Hardware Power Switch

Battery Power

Full Charge

Low Charge

The Model 831 is compatible with AA nickel metal hydride
(NiMH), Alkaline or 1.5 Volt Lithium batteries. Energizer,
Duracell and other nationally recognized brands are the
preferred suppliers of alkaline batteries. These will provide
the user with the best battery life estimation. Sanyo,
Energizer and Ray-O-Vac, 2500 mAH, Lithium, AA, NiMH
batteries and their respective fast chargers are also
recommended.

WARNING:Do not mix Alkaline and NiMH batteries.

WARNING:Do not mix batteries from different

manufacturers

WARNING:Replace all four batteries when installing
fresh cells

WARNING:The correct battery type must be specified,
as described in "Battery Type" on page 18-5, based on
the battery type installed. Otherwise, serious damage,
injury or fire can occur when the battery type is set to
NiMH but Alkaline or Lithium batteries are installed
because the internal charger will be enabled. Alkaline or
Lithium batteries must not be charged.

Model 831 Manual Powering the Model 831 2-5

Battery Voltage an d Estimated Run Time are displayed on
the Power Control screen and the last page of the Live tab.
The battery icon indicates the state of the battery charge by
the width of the interior shaded portion. Figure 2-6 shows a
fully charged battery and a nearly discharged battery.

FIGURE 2-6 Battery Status Icons

A battery icon is always available in the status bar at the top
of the screen. The battery voltage and the state of the battery

Low Battery

Inserting Batteries

icon directly reflect the remaining Estimated Run Time as
displayed by the instrument.

As the battery nears end-of-life (1% of capacity), the empty
battery symbol will begin to flash. The unit will shut down
in a short time because the battery voltage is too low.

When the battery is at the end-of-life, the Model 831 will
stop running, save all data and instrument status, then turn
off. When the unit is turned on again, with fresh batteries or
an external power supply, the unit returns to the state it was
in when it shut down.

If external power is supplied through the USB connector, the
battery icon is replaced with the External Power icon, as
shown in Figure 2-7.

FIGURE 2-7 External Power Icon

When external power is connected to the Model 831, the
unit is not dependent on batteries. The Estimated Run Time
calculation is valid only if there is no external power.

There are 2 tabs on the bottom of the
battery door that engage the case of
the Model 831.

2-6 Powering the Model 831 Model 831 Manual

The battery compartment of the Model 831 is located on the
back of the unit. There is a clip on the battery door. To
remove the battery door, place a finger on the clip and push
it downward towards the battery door while pulling away
from the body of the instrument. The battery door will pivot
away from the unit.

Insert 4 fresh AA batteries as shown in FIGURE 2-8. Ensure
correct alignment of the batteries + and - terminals as
indicated by diagrams on the bottom of the battery
compartment.

FIGURE 2-8 Insert Batteries

After the batteries are installed, insert the two tabs on the
bottom edge of the battery door into the mating slots in the
case. Close the battery door, allowing the clip to snap in
place on the case.

Selecting Battery Type

The battery type is selected from the Power tab in System
Properties, as described in the section “Battery Type” on
page 18-5.

Charging Batteries On-board

When using NiMH batteries and powering the Model 831
from either the computer (via USB port) or from the
PSA029 power supply, or from another external source, the
batteries will be charged inside the instrument. The charge
time to completely recharge the cells is about sixteen hours
when the instrument is powered off. The batteries will be
charged while the instrument is powered on at a reduced rate
as long as the backlight and USB Host features are off.

Model 831 Manual Powering the Model 831 2-7

Charge Status LED

External Power Supply

USB Port Power

The charge status is indicated by an LED beneath the power
key as follows:

• LED continuously lit: Charging

• LED not lit: Not charging

• LED flashing at 1/sec: Trickle charging. This is

typically done early in the charging cycle when the
battery is cold, or when the battery has been highly
discharged. The charge rate should increase when these
conditions improve.

The Model 831 can be powered from a variety of sources
including internal batteries, via the USB port from a
computer, via the USB port from the PSA029 power supply,
via the I/O port from the PSA027 power supply (using
CBL140 or CBL154), from an external +10.8 to +30 Volt
battery, or from an external +10.8 to +30 Volt mains power
source.

When powering the Model 831 by
external power, Larson Davis
recommends the Model 831-INT
System Interface Unit and the
appropriate Larson-Davis cable for
making the connection to the battery
or batteries.

The PSA029 is supplied with power
plug adaptors for most areas of the
world.

If the Model 831 is operated without
batteries installed and power is
interrupted, data may be lost.

2-8 Powering the Model 831 Model 831 Manual

When powered via the USB port by a computer, use of the
computer's USB power is negotiated with the host and
cannot be utilized until permission is granted by the host.
This means that the Model 831 must run on batteries until
allowed by the host to run on USB or external power. If the
batteries cannot provide sufficient power (flat cells) the
Model 831 may not power on. Ensure that the Model 831
has good batteries in order to turn on. If there are no
batteries installed in the instrument, it will use USB power
regardless of negotiation.

The Model 831 can be powered via the USB port with the
PSA029 external power supply. The PSA029 has an input
operating voltage range of 90 to 274 VAC and a power line
frequency range of 47 to 63 Hz. The output voltage from the
supply is 5 VDC. The PSA029 used a standard USB A to
Mini-B 5-pin cable which connects to the USB connector on
the bottom of the Model 831.

With the PSA029 power supply connected and operating at
rated conditions, the Model 831 will operate properly with
or without batteries installed.

Low Voltage Shutdown

Power Outage

Sudden Loss of External Voltage

The Model 831 has a special feature to preserve the service
life of an external SLA (Sealed Lead-Acid) battery by
preventing it from being discharged excessively. When the
battery voltage drops below the external shutoff voltage
(default value +10.8 volts), but remains above +10.2 volts
for one minute, the instrument will stop, save data and turn
the Model 831 off.

In the event of power outage, unattended Model 831 meters
with serial numbers greater than 2089 will turn on
automatically in six hours as a recovery mechanism.

WARNING!
A sudden loss of power while the
Model 831 is storing data may lead
to hardware damage and should be
avoided. To avoid this, turn off the
Model 831 prior to turning off the
PC, or before unplugging USB
cables from the PC.

Power-Up Operation

Insufficient Battery Voltage

If the external voltage is suddenly lost, for example when
the external supply is disconnected or when mains power
fails and there is no external battery, the Model 831 will
continue to run on internal batteries if they are present and in
good condition. Without internal batteries, the Model 831
will shut-down and un-stored data may be lost.

The Model 831 automatically detects its power source while
it is turning on and does not fully start if a problem is found.

If the internal battery is powering the instrument, i.e. there is
not USB or external power, and is less than ~4.2 Volts, the
display shown in FIGURE 2-9 appears with the grey box
inside

FIGURE 2-9 Insufficient Battery Voltage

Model 831 Manual Powering the Model 831 2-9

Insufficient External Voltage

If the external power source is operating the instrument, i.e.
there is no USB or internal battery power available, and is
less than about 10.8 Volts, the displa y shown in FIGURE 2­10 appears with the grey box inside the battery symbol
flashing on and off every second.

FIGURE 2-10 Insufficient External Voltage

If the power fault condition is not alleviated within 2
minutes, the instrument powers off. If a sufficient power
supply is provided for more than 10 seconds, i.e. USB or
Main power is connected, the instrument proceeds to turn
on.

2-10 Powering the Model 831 Model 831 Manual

Power Control Page

The estimated battery run time is
only shown after running on
batteries for more than one minute,
which permits the battery voltage to
stabilize.

If the Model 831 is ON, pressing the
displays the Power Control screen.

FIGURE 2-11 Power Control View

Located on the first section of this screen is the Estimated
Battery Run Time (calculated using the voltage of the

installed batteries), Battery Voltage and the USB Powered
voltage.

0 (ON/OFF) key

For more information on Backlight
and Display Contrast, see the
"Backlight" on page 18-9 and
"Display Contrast" on page 18-9.

The units of the temperature display
are user-selectable, as described in
“Units” on page 18-22.

Model 831 Manual Powering the Model 831 2-11

Next, Backlight and Display Contrast are adjusted using
the 4, 6, 8 and 2 keys. Backlight provides three
options: Off, Dim and Bright, which are adjusted using the
4 and 6 keys. The Display Contrast has a range of -9 to 9,
which is adjusted using the 8 and 2 keys.

The last section displays the Model 831 internal temperature
that is used to automatically adjust the contrast of the display
to compensate for temperature changes.