Larson Davis System 824 Reference Manual
System 824
Reference Manual
Larson Davis Inc.
1681 West 820 North
Provo, UT 84601-1341
Phone: (801) 375-0177
FAX: (801) 375-0182
www.larsondavis.com
I824.01 Rev. g
824 Reference Manual
Copyright
Copyright 2000 by Larson Davis, Incorporated. This manual and the software described in it are copyrighted, with all rights reserved. The software may not be copied in whole or in part for commercial
use without prior written consent of Larson Davis Inc. The manual may not be copied in whole or in
part for any use without prior written consent of Larson Davis Inc.
Disclaimer
The following paragraph does not apply in any state or country where such statements are not agreeable with local law:
Even though Larson Davis, Inc. has tested the software and reviewed its docu mentation, Larson Davis
Incorporated makes no warranty or representation, either expressed or implied, with respect to this
software and documentation, its quali ty, performance, merchantability, or fitness for a particular purpose. This documentation is su bject to change with out notice, and shou ld not be constru ed as a commitment or representation by Larson•Davis Inc.
This publication may contain inaccuracies or typographical errors. Larson Davis 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.
Warranty
Larson Davis warrants this product to be free from defects in material and workmanship for two years
from the date of the original purchase. During the two year warranty period, Larson Davis will repair
or, at its option, replace any defective component(s) without charge for parts or labor if the unit is
returned, freight prepaid, to an authorized service center. The product will be returned freight prepaid.
Product defects caused by misuse, accidents, or user modification are not covered by this warranty.
The warranties described above are exclusive and in lieu of all other warranties whether statutory,
express or implied including, but not limited to, any implied warranty of merchantability or fitness for
a particular purpose and all waranties arising from the course of dealing of usage or trade. The buyer’s
sole and exclusive remedy is for repair or replacement of non-conforming product or part thereof, or
refund of the purchase price, but in no event shall Larson Davis ( its contractors or suppliers of any
special indirect, incidental, or consequential damages) whether the claims are based in contract, in tort
(including negligence), or otherwise with respect to or arising out of the product furnished hereunder.
Representation and warranties made by any person, including its authorized dealers, representatives,
and employees of Larson Davis which alter or are in addition to the terms of this warranty shall not be
binding upon Larson Davis unless in writing and signed by one of its officers.
Larson Davis is an equal opportunity employer and does not discriminate on the basis of race, color,
religion, gender, national origin, disability or veteran status.
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824 Reference Manual
Please examine your instrument and record the following information below. You may be asked to
give this information in any future communications you have with Larson Davis, Inc.
Record of Serial Number and Purchase Date
System 824 Serial #: _____________________
Microphone Model #: ___________________
PRM902 Pre-am p. Serial #: ______ ________
Microphone Serial # ____________________
Purchase Date: _________________________
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Table of Contents
Chapter 1 Introduction 1-1
About This Manual.................................................................................................1-1
About This Chapter.................................................................................................1-3
Formatting Conventions .........................................................................................1-3
Features...................................................................................................................1-4
System 824 Components....................................................................................1-7
System Diagram...............................................................................................1-10
Getting Started.................................... .................................. ...... ..... .....................1-10
Unpacking and Inspection.......................................... ......................................1-12
Accessories and Optional Equipment ..............................................................1-12
Connecting Internal or External Power............................................................1-13
Using the NiMH Battery Pack ....................................................................1-14
Using Alkaline Batteries .............................................................................1-14
Using the AC Power Adapter......................................................................1-15
Chapter 2 Overview 2-1
System 824 Setups or Instrument Definitions........................................................2-1
Instrument Definition (ID) Types ..........................................................................2-2
SLM&RTA (SSA) .............................................................................................2-2
SLM (ISM) ........................................................................................................2-4
Logging (LOG)..................................................................................................2-4
Selecting a Measurement Setup..............................................................................2-5
Performing a Measurement; SLM&RTA (SSA) example......................................2-6
Stop, Pause and Back Erase Functions ..............................................................2-7
Stopping and Starting Measurements........................................... ...... ...........2-7
Pausing Measurements..................................................................................2-7
Back Erasing .................................................................................................2-8
Changing the detector of the displayed SPL value ............................................2-8
Changing the frequency weighting of the displayed SPL value........................2-9
Changing the displayed secondary parameter....................................................2-9
Changing the frequency weighting of the displayed Lpeak value...................2-10
Changing the amplitude range, or input Gain..................................................2-10
Views ....................................................................................................................2-11
Selecting a VIEW.............................................................................................2-11
Data Storage and Recall........................................................................................2-13
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824 Reference Manual
Storing Data.................................................................................................2-13
Recalling Data.............................................................................................2-13
Calibration ............................................................................................................2-14
Chapter 3 Front Panel Keys; their Functions and Menus 3-1
Power Key.........................................................................................................3-3
Power-up the Instrument / Viewing PWR Display............................................3-4
Power Settings...................................... ..... ...... .................................. ...... ..... ......3-6
Extra Notes on Power Conservation..................................................................3-8
Run/Stop Key....................................................................................................3-9
Reset Key ..........................................................................................................3-9
Pause Key........................................................................................................3-10
Pause............................................................................................................3-10
Pause, Back Erase .......................................................................................3-10
Preview........................................................................................................3-11
Check Key........................................................................................................3-12
View Key.........................................................................................................3-12
Data Key..........................................................................................................3-13
Setup Key ........................................................................................................3-14
Save ID........................................................................................................3-16
Title .............................................................................................................3-16
ID Name......................................................................................................3-16
Write Protect, Delete, Write Enable IDs..........................................................3-16
Tools Key......................................................................... ................................3-17
About.............................................. .................................. ................................3-19
Calibration........................................................................................................3-22
Clock/Timer.....................................................................................................3-23
Memory.................................... .................................................................... ....3-27
Deleting Stored Data............................................. ..... ......................................3-28
Delete Last Function ...................................................................................3-28
824 Memory Structure ................................................................................3-29
Deleting the Last Stored Record .................................................................3-29
Deleting Individual Records.................................. ...... ................................3-31
Power Monitor ...................................................... ..... ...... ................................3-32
Communication.................................... ..... .................................. ...... ...... .........3-33
Print Key..........................................................................................................3-36
Arrow Keys.................................................................................3-11
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824 Reference Manual
Chapter 4 Quick Start 4-1
Turning On and Calibrating the System 824 ..........................................................4-1
Taking Measurements and Storing Data.................................................................4-3
SLM&RTA Measurements................................................................................4-3
Viewing RTA Displays during a Measurement...................................... ..... ......4-6
Recalling Stored Data.............................................................................................4-8
Selecting and Modifying Instrument Definitions (IDs)........................................4-10
The Setup Menu...............................................................................................4-11
The Active ID...................................................................................................4-11
Menu Scrolling.................................................................................................4-12
Permanent IDs..................................................................................................4-13
Write-protected IDs..........................................................................................4-13
Preparing for a Measurement........................................... ...... ..........................4-14
Selecting a Different ID...................................................................................4-14
Accessing the Settings Menu...........................................................................4-14
Accessing the Settings Menu to Initiate Editing or Modification....................4-16
Setting Control in the SLM View....................................................................4-19
Chapter 5 System 824 Virtual Instruments 5-1
System 824 Virtual Instruments .............................................................................5-1
Selecting an Instrument ID.....................................................................................5-3
Combined SLM&RTA ...........................................................................................5-3
SSA Measuring Ranges ........................................ ..... ........................................5-4
AC/DC Output ...................................................... .................................. ...........5-5
Logging SLM..........................................................................................................5-6
Time History......................................................................................................5-7
Interval History..................................................................................................5-7
Exceedances.......................................................................................................5-7
LN Percentiles (Broadband)...............................................................................5-8
LN Percentiles (Spectral)...................................................................................5-8
Sound Exposure.................................................................................................5-9
LOG and ISM Measuring Ranges......................................................................5-9
Chapter 6 System 824 Views 6-1
Status Icons and Indicators.....................................................................................6-2
General Views....................................................................... ..................................6-4
SLM Views ........................................................................................................6-4
Any Data View...................................................................................................6-7
Any Level Format .........................................................................................6-7
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SSA Specific Views................................................... .............................................6-9
Logging SLM Specific Views ..............................................................................6-23
Any Impulse Format............................. .........................................................6-8
Any Time Format.................................................................................... ......6-8
SSA Displays ............................................................. ...... ................................6-11
RTA Displays..............................................................................................6-11
Tabular RTA Views....................................................................................6-11
Time History Displays ................................................................................6-12
SSA Time History.......................................................................................6-16
Run Log............................................................ .................................. ..... ....6-19
Ln Centiles ................................................. .................................. ...............6-19
Current SLM and Overall SLM Views............................................................6-25
Current SLM/Overall SLM Display-a (SPL)..............................................6-26
Current/Overall SLM Display-b (Times)....................................................6-28
Current/Overall SLM Display-c (Min/Max)...............................................6-29
Current/Overall SLM Display-d (Peaks).....................................................6-29
Current/Overall SLM Display-e (TWA).....................................................6-30
Exposure Views ...............................................................................................6-31
Exposure Display-a.....................................................................................6-31
Exposure-b Display.....................................................................................6-33
Exposure-c Display.....................................................................................6-34
Ln Centiles Views............................................................................................6-35
Ln-a Display................................................................................................6-35
Ln-b Display................................................................................................6-36
Stats Views.......................................................................................................6-37
Stats-a Display.............................................................................................6-37
Stats-b Display ............................................................................................6-38
Stats-c Display.............................................................................................6-39
Run Log (LOG & SSA) ...................................................................................6-40
Time History....................................................................................................6-41
Intervals............................................................................................................6-43
Intervals-a Display ......................................................................................6-43
Intervals-b Display............................................................ ..... .....................6-44
Intervals-c Display ......................................................................................6-46
Intervals-d Display............................................................ ..... .....................6-47
Intervals-e Display ......................................................................................6-48
Exceedance History..........................................................................................6-49
Excd-a Display............................................................................................6-49
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Excd-b Display..................................... .......................................................6-50
Excd Time History Display.........................................................................6-51
Daily Views......................................................................................................6-53
Daily-a Display ...........................................................................................6-53
Daily-b Display...........................................................................................6-55
Hourly Leq Display .....................................................................................6-56
Metrics .............................................................................................................6-57
Metrics-a Display........................................................................................6-57
Metrics-b Display....................................... .................................................6-58
PassBy........................................................................ ...... ...... ..........................6-59
Chapter 7 Using ID Setting Files 7-1
Recalling ID Setting Files.......................................................................................7-1
Customizing Settings..............................................................................................7-2
Settings Example - SLM&RTA (SSA)..............................................................7-2
Settings Descriptions ..............................................................................................7-4
Common SLM Settings......................................................................................7-5
Title Setting - (
Detector Setting - (
Weighting Setting - (
Gain Setting - (
Range Setting - (
Transducer Setting - (
SSA, LOG, ISM
SSA, LOG, ISM
SSA, LOG, ISM
) .....................................................................................7-6
SSA
LOG, ISM
SSA, LOG, ISM
Random Incidence Microphone Correction - ...............................................7-8
Pk Weighting - (
SSA, LOG, ISM
RTA Detector Setting - (
RTA Weighting - (
Bandwidth Setting - (
)................................................................................ 7-9
SSA
SSA
Common Control Settings..................................................................................7-9
AC/DC Output Settings - (
Logic Input Setting - (
Logic Output Setting - (
SSA, LOG, ISM
SSA, LOG, ISM
Logic Output Time Setting - (
Logic Output #2 ..........................................................................................7-14
Logic Output #2 Time Setting.....................................................................7-14
Heater On ....................................................................................................7-14
E. A. Cal Tone.............................................................................................7-14
Logging SLM TWA Settings...........................................................................7-15
Ovll Exchange - (
)...............................................................................7-15
LOG
)..................................................................7-5
)............................................................7-5
).........................................................7-6
).........................................................................7-6
)........................................................7-7
)................................................................7-8
) ........................................................... ...........7-8
SSA
)............................................................................7-9
SSA, LOG, ISM
)..............................................7-11
).....................................................7-11
)..................................................7-11
SSA, LOG, ISM
).........................................7-13
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824 Reference Manual
Ovll Threshold - (
Ovll Criterion - (
Criterion Time - (
Crnt Exchange - (SSA,
) ..............................................................................7-16
LOG
)................................................................................7-16
LOG
)...............................................................................7-17
LOG
ISM, LOG
)............................................................7-17
Crnt Threshold (SSA, ISM, LOG)..............................................................7-18
Crnt Criterion (LOG) ..................................................................................7-18
LOG and SSA Ln Settings...............................................................................7-18
Enable Ln ....................................................................................................7-19
Start Level....................................... .................................. ..........................7-19
Ln’s .............................................................................................................7-20
Spectral Ln’s (SSA only) ............................................................................7-20
LOG and SSA Triggering Settings..................................................................7-21
SPL Excd Lvl 1 - (
SPL Excd Lvl 2 - (
PK Excd Lvl 1 - (
Pk Excd Lvl 2 - (
Hysteresis - (
LOG, SSA
LOG, SSA
LOG, SSA
LOG, SSA
LOG, SSA
)............................................... ...... ........... ....7-21
)............................................... ...... ........... ....7-21
) ............................... ...... ...... ........... ...... .........7-22
) ......................................................................7-22
).............................................................................7-22
LOG and SSA Time History Settings..............................................................7-23
Hist Enable - (
Hist Period (
LOG, SSA
Period Units - (
Other Level - (
Resolution - (
LOG, SSA
LOG, SSA
LOG only
LOG, SSA
)...........................................................................7-25
)..............................................................................7-25
).........................................................................7-25
) ...........................................................................7-26
)............................................................................7-27
Advanced Time History - (LOG, SSA).......................................................7-27
Marker Text - (LOG, SSA).........................................................................7-28
LOG and SSA Interval Settings.......................................................................7-28
Intv Enable - (
Intv Period - (
LOG, SSA
LOG, SSA
Intv Time Sync - (
)............................................................ ...............7-29
) ................................ ..... ...... ...... ........... ...... ..... ....7-29
LOG, SSA
) ....................................................................7-30
Intv Save Ln’s - (LOG, SSA)......................................................................7-30
Intv Auto Stop - (
Intv Threshold - (
Intv Exchange - (
LOG, SSA
LOG, SSA
LOG, SSA
)......................................................................7-30
)......................................................................7-31
)........................... ........... ...... ........... ...... ..... ....7-31
Intv Spectrum - (SSA only).........................................................................7-32
Logging SLM Exceedance History Settings....................................................7-32
Triggering - (
Excd Enable - (
Min Duration - (
)......................................................................................7-32
LOG
) ..................................................................................7-32
LOG
).................................................................................7-32
LOG
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824 Reference Manual
Excd Time Hist - (
T.H. Period - (
Excd Trigger - (
Excd Time - (
LOG
LOG
LOG
) .............................................................................7-33
LOG
)....................................................................................7-33
) .................................................................................7-33
).....................................................................................7-33
Logging SLM Daily History Settings..............................................................7-34
Daily Enable - (
Daily Ln’s - (
)..................................................................................7-34
LOG
) .....................................................................................7-34
LOG
Logging SLM Define Report Settings.............................................................7-34
Data Report - (
LOG, SSA
)..........................................................................7-35
Setup Report - (LOG, SSA) ............................. ..... ...... ................................7-35
SPL Histogram - (
Pk-1 Histogram - (
Pk-2 Histogram - (
Intv Report - (
Hist Report - (
LOG, SSA
LOG, SSA
)..............................................................................7-36
LOG
).............................................................................7-36
LOG
).............................................................................7-36
LOG
)...........................................................................7-36
)............................................................ ........... ....7-37
Menu Layout of SSA Settings..............................................................................7-37
Menu Layout of Integrating SLM (ISM) Settings................................................7-43
Menu Layout of Logging SLM Settings...............................................................7-46
Check Menus ....................................................... ...... ..... ......................................7-52
Check Menu Example......................................................................................7-53
SLM Check Menu Options (SSA and LOG)...................................................7-55
Mark Display....................... ........................................................................7-55
Graph Menu.................................................................................................7-57
Settings........................................................................................................7-58
Controls Settings Menu...............................................................................7-58
Other SSA Check Menus...................................... ...........................................7-58
Any Data Check Menu.......................................... ......................................7-58
RTA Check Menu.......................................................................................7-59
Intervals Check Menu .................................................................................7-60
Time History Check Menu..........................................................................7-61
Run Log Check Menu...................................... ...........................................7-62
Ln Centiles Check Menus................................ .................................. .........7-63
Other Logging (LOG) Check Menus...................................................... ..... ....7-66
Any Data Check Menu.......................................... ......................................7-66
Current SLM / Overall SLM Check Menu..................................................7-66
Exposure Check Menu................................................................................7-66
LN Centiles Check Menu............................................................................7-67
Stats Check Menu........................................................................................7-68
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Run Log Check Menu...................................... ...........................................7-68
Time History Check Menu..........................................................................7-69
Intervals Check Menu .................................................................................7-69
Excd History Check Menu..........................................................................7-70
Daily History Check Menu .........................................................................7-71
Chapter 8 Printing a Report 8-1
Connecting the 824 to a Serial Printer....................................................................8-1
Printing Reports.................................. ....................................................................8-2
Defining and Printing Tailored Reports..................................................................8-5
Using the Recall Format (SSA and LOG instruments only)..............................8-7
Default Settings Values for the Recall Format Reports ................................8-8
Printing a Custom Report .............................. .......................................................8-22
Chapter 9 Using the 82 4 Ut ility Software 9-1
824 Utility Software Overview...............................................................................9-1
824 Utility Installation............................................................................................9-1
Starting the 824 Utility Software............................................................................9-2
Connecting the 824 to Your Computer...................................................................9-2
824 Utility Tool Bar................................................................................................9-4
824 Utility Setup Window......................................................................................9-6
Retrieving setups from the 824............................................................... ...........9-7
Modifying and Storing Setups to the 824 .................................................... ......9-9
Manipulating a Setup ..................................................................................9-10
Saving Setups to Disk Files .............................................................................9-12
Opening Setup Disk Files ................................................................................9-12
Creating a New Setup ........................................... ...........................................9-14
Renaming an Existing Setup....................................................... .....................9-15
Deleting an Existing Setup..................................................... ..... ...... ...............9-16
Locking and Unlocking Setups........................................................................9-17
Downloading Measurement Data .........................................................................9-17
Specifying a Destination File...........................................................................9-18
Changing the Download File Name.................................................................9-20
Adding Notes to a download file .......................... ...........................................9-21
Selecting Active Measurements or Data Files.................................................9-21
Downloading the measurement........................................................................9-22
Explanation of files in the 824 Utility Directory .............................................9-24
Translating Measurement Data from a Downloaded Binary File.........................9-25
Selecting a Data set to view.............................................................................9-27
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824 Reference Manual
Printing a Translated File........................................... ......................................9-29
Viewing a Translated File Within a Spreadsheet Program..............................9-31
Additional Features...............................................................................................9-32
Chapter 10 RTA (optional) 10-1
Settings Menu .......................................................................................................10-2
Settings Descriptions ............................................................................................10-5
RTA Settings Menu .........................................................................................10-5
Autostore Settings Menu..................................................................................10-7
Arm Settings Menu................................... .................................. ...... ...............10-8
Trigger Settings Menu .............................. ...... ...... .................................. ..... ..10-10
End Settings Menu.........................................................................................10-11
Then Settings Menu.......................................................................................10-12
Trigger Settings Menu (continued)......................................................... ..... ..10-13
RTA Settings..................................................................................................10-15
RT60-A and RT60-B Instrument Definition..................................................10-16
Rooms RTA Instrument Definition................................................................10-17
Display Views .....................................................................................................10-18
RTA Views ....................................................................................................10-18
Trigger Views .......................... ...... ...... ..........................................................10-22
Autostore Views.............................................................................................10-25
Autostore ByTime Spectral History...............................................................10-29
ByTime Spectrum Check Menu.....................................................................10-30
ByTime Graph Check Menu..........................................................................10-31
RT-60.............................................................................................................10-33
RT60 Check Menu.................................................................................. ..... ..10-35
Spatial Avg Views .........................................................................................10-35
Spatial Avg Check Menu...............................................................................10-37
Avg History Check Menu.......................................... ...... ..............................10-38
Rooms Views.................................................................................................10-39
Chapter 11 FFT (Optional) 11-1
Features.................................................................................................................11-1
Settings Menu .......................................................................................................11-1
Settings Descriptions ............................................................................................11-3
FFT Display..........................................................................................................11-6
FFT...................................................................................................................11-6
FFT Check Menu.............................................................................................11-8
THD (Total Harmonic Distortion)........................................................................11-8
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824 Reference Manual
THD Check Menu..........................................................................................11-10
Snapshot..............................................................................................................11-11
Snapshot Check Menu ...................................................................................11-11
Entering Linear Units..................................... ...... ...... .................................. ..... ..11-12
Chapter 12 AUD (Optional) 12-1
Selecting the 824-AUD Operation Mode .............................................................12-2
SLM+RTA Mode................................................. .................................................12-3
SLM+RTA Live screen....................................................................................12-3
Any Level-a Screen..........................................................................................12-4
FFT Mode.............................................................................................................12-5
FFT Screen.......................................................................................................12-5
THD (Total Harmonic Distortion)...................................................................12-6
Linearity...........................................................................................................12-9
Pulse/FM Mode...................................................................................................12-11
Pulse/FM-a Screen.........................................................................................12-11
Pulse/FM-b Screen.......................................... ...............................................12-14
Pulse/FM Check Menu...................................................................................12-15
Appendix A Integrated Level Calculations A-1
Basic Integrated Level Calculations......................................................................A-1
Appendix B Serial Port Interface Remote Control B-1
Interface Cables .....................................................................................................B-2
Connection to a computer using CBL006.......................................... ..........B-2
Daisy Chain Addressing ........................................................................................B-3
824 Network, Addressing Commands..............................................................B-3
Commands.............................................................................................................B-5
Remote Control Commands (Detailed).................................................................B-6
Mode Commands..............................................................................................B-6
“Read” Commands (Reads out data variables).................................................B-7
“ANY DATA” READ COMMANDS............................................................B- 21
Other Read Commands........................ ...........................................................B-23
Group Read Programming..............................................................................B-23
Setting Commands...............................................................................................B-24
Querying Settings............................................ .................................. ..............B-25
Ln Query Commands (SSA).................................................. ..... ....................B-26
Entering Settings........................................................ ...... ...............................B-26
Option Settings..................................... ......................................................B-26
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824 Reference Manual
Numeric Settings........................................................................................B-28
Character String Settings........................................................ ...... ..............B-28
Template Settings.......................................................................................B-28
Setting List...........................................................................................................B-29
Histogram Reports ..................................................... .................................. ...B-36
Tailored Report ..........................................................................................B-37
Miscellaneous.............................................................................................B-37
Error Checking I/O ................................... ...... ...... ..........................................B-40
RTA Settings Commands................................................................................B-42
History Records.............................. ...... ..... ......................................................B-45
Types of History.........................................................................................B-46
Advance......................................................................................................B-46
Backup........................................................................................................B-46
Find.............................................................................................................B-47
History Data Variables............................................... ..........................................B-47
Exceedance History Variables........................................................................B-47
Interval History Variables (“I” Commands)............................... ....................B-49
Daily History Variables - (D1-D102) .................................................... ..... ...B-54
Run Log Variables (SSA, ISM, LOG, TAL).......................................... ..... ...B-56
Calibration History Variables (LOG) .............................. ...............................B-56
Time History Variables (SSA, LOG, TAL) ...................................................B-57
Time History Variables (SSA, LOG, TAL)....................................................B-58
Histogram Table Variables ......................................................... ....................B-58
Print Commands ..................................................................................................B-59
Error Messages and Warnings......................................................... ...... ..............B-61
Modem Control Mode (All Instruments).............................................................B-64
Modem Mode..................................................................................................B-64
Dial Out Mode ................................................................................................B-64
Monitor Number .............................................................................................B-65
824 Phone Dialing Procedure .........................................................................B-65
Model 824 Answering Procedure ...................................................................B-66
Unsupported Miscellaneous Commands .............................................................B-67
Data File Commands ........................................................................................... B-68
Keyboard Simulation...........................................................................................B-69
Operation Notes...................................................................................................B-70
Appendix C Technical Specifications C-1
Declaration of Conformity................................................................................C-2
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Appendix D Glossary D-1
Allowed Exposure Time (Ti) .......................................................................D-1
Average Sound Level (Lavg).......................................................................D-1
Calibration....................................................................................................D-2
Community Noise Equivalent Level (CNEL, Lden)....................................D-2
Criterion Duration (Tc) ..................................................... ...........................D-2
Criterion Sound Exposure (CSE)............................................................ .....D-3
Criterion Sound Level (Lc)..........................................................................D-3
Daily Personal Noise Exposure (LEP,d)......................................................D-3
Day-Night Average Sound Level (DNL, Ldn).............................................D-3
Decibel (dB).................................................................................................D-4
Department of Defense Level (LDOD)........................................................D-5
Dose..............................................................................................................D-5
Detector........................................................................................................D-5
Eight Hour Time-Weighted Average Sound Level (L TWA(8)).................D-5
Energy Equivalent Sound Level (Leq).........................................................D-5
Exchange Rate (Q), Exchange Rate Factor (q), Exposure Factor (k)..........D-6
Far Field .......................................................................................................D-6
Free Field......................................................................................................D-6
Frequency (Hz, rad/sec) ...............................................................................D-7
Frequency Band Pass Filter.......................................................... ................D-7
Frequency Filter - Weighted ................................. .................................. .....D-8
Leq................................................... .............................................................D-9
Level (dB) ....................................................................................................D-9
Measurement Duration (T).........................................................................D-10
Microphone Guidelines..............................................................................D-10
Near Field............................................. ...... ...... ..........................................D-12
Noise............................... ..... ...... .................................................................D-13
Noise Dose (D)...........................................................................................D-13
Noise Exposure ..........................................................................................D-13
OSHA Level (LOSHA)..............................................................................D-14
Preamplifier................................................................................................D-14
Projected Noise Dose.................................................................................D-14
Single Event Noise Exposure Level (SENEL, LAX) ................................D-14
Sound..........................................................................................................D-14
Sound Exposure (SE).................................................................................D-14
Sound Exposure Level (SEL, LET)...........................................................D-15
Sound Pressure........................................................................................... D-15
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824 Reference Manual
Sound Pressure Level (SPL, Lp)................................................................D-16
Sound Power(W)........................................................................................D-18
Sound Power Level (PWL, Lw).................................................................D-18
Sound Speed, (c,) .......................................................................................D-18
Spectrum (Frequency Spectrum)................................................................D-18
Threshold Sound Level (Lt).......................................................................D-18
Time Weighted Average Sound Level (TWA, LTWA(TC)).....................D-19
Time Weighting..........................................................................................D-19
Vibration.....................................................................................................D-19
Wavelength (l)....................................................... .....................................D-19
Wavenumber (k).........................................................................................D-20
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824 Reference Manual
xiv
CHAPTER
Introduction
1
About This Manual
Welcome to the Larson Davis System 824. 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.
This manual has 12 chapters and 4 appendices covering the
following topics:
Chapters
•
Chapter 1 - Introduct ion:
tents of this user manual and the System 824’s features,
functions and measurement capabilities . It also includes
instructions on unpacking the System 824.
•
Chapter 2 - Overview:
instrument’s capabilities and a description of each key
along with its function and displays. It also includes
instructions on working with menus.
•
Chapter 3 - Front Panel Keys; their Functions and
Associated Menus:
with each key on the 824.
•
Chapter 4 - Quick Start:
use of the System 824 including how to take measurements, understanding the readings, and storing data in
the System 824.
11/8/00 Introduction 1-1
Orients the user to the con-
Provides an overview of the
Explains the functions associated
Guides users in the immediate
•
Chapter 5 - System 824 Instrument Modes
: Provides
descriptions of the System 824’s standard instrument
ID’s.
•
Chapter 6 - System 8 24 Views:
Gives you a detailed
description of the different display views available and
how to access them.
•
Chapter 7- Using ID Se tting Files:
Describes how to
recall, customize and save IDs.
•
Chapter 8 - Printing a Repo r t:
Describes how to print
a report of the data collected with the System 824.
•
Chapter 9 - Using the 824 Utility Software:
Describes
how to connect the 824 to a computer, in order to download, translate and export data.
• Chapte r 10 - RTA (Optional):
Explains how the RTA
high speed data gathering option enables you to perform
architectural acoustics, impulse event analysis, and
passby event analysis.
•
Chapter 11 - FFT (Optional):
Describes the features
and functions of the fast fourier analysis option.
•
Chapter 12 - AUD (Optional):
Explains how the AUD
option can be used to manually test an audiometer by
measuring level, frequency, linearity, THD, pulse,
crosstalk, frequency modulation, narrow band, broad
band, and speech noise.
1-2 824 Reference Manual 11/8/00
Appendices
•
Appendix A - Integrated Level Calculations:
Provides
information on TWA Leq, SEL, dose and projected dose
calculations.
•
Appendix B - S erial Port Rem ote Control Inter face:
Explains how to use the Serial Port Interface for Remot e
Control of the System 824.
•
Appendix C - Technical Specifications:
Gives a listing
of acoustic, electronic, environmental, and physical characteristics of the System 824
About This Chapter
•
Appendix D - Glossary:
tions of key acoustical and vibration terms.
This introductory chapter covers the following topics:
Contains Technical Defini-
Formatting
•
Formatting Conventions:
the fonts and o ther formatting conven tions used in this
manual.
•
Features:
functions and measurement capabilities.
•
Getting Started:
inspecting and initially assembling the Syst em 824.
Gives an overview of the System 824 keypad,
Provides instructions for unpacking,
Provides an explanation of
11/8/00 Introduction 1-3
This manual uses the following format conventions:
In step-by-step directions, the
shown in the right colu mn, and t he
with other cautions and comments are shown in the left column.
process
(what you do) is
rationale
(why you do i t )
Keys to press on the System 824 are shown with the icon
representing the appropriate key. For example:
Features
Press the
Items that appear in various on-screen menus (such as settings) are shown in bold and italicized style. For example:
Detector [Slow]
The Larson•Davis System 824 has the following features:
• Large backlit bitmapped graphic display
• Soft rubber backlit keys
• Pop-up menus with scroll bars
• Pick and choose setup...just click and run!
• File management system (stores multiple measurements)
• Multiple instruments:
v
key
SSA: Sound Spectrum Analyzer combining a
sound level meter and real-time spectrum analyzer
(optional)
LOG: Logging SLM (optional)
ISM: Integrating SLM (standard)
RTA: Adds high speed spectral data gathering
(optional)
FFT: Adds fast fourier analysis to the 824
(optional)
1-4 824 Reference Manual 11/8/00
AUD: Gives the 824 the ability to certify audiometers; used in conjunction with the AUDit software (optional)
TAL: Measures tonality according to DIN 45681
and appraisal of low frequencies according to DIN
45680 (optional)
• Type 1 precision integrating sound level meter (satisfies
IEC 60651-1993, IEC 60804-1993, and ANSI S1.4
1985)
• Simultaneous measurement of sound pres sure le vel usi ng
Fast, Slow, Impulse, Peak, and Leq detectors with A, C,
and Flat weighting (SSA, ISM, LOG, and TAL instruments)
• Exceptionally large dynamic range (> 93 dB for SSA and
> 115 dB for ISM and LOG)
• Digital filters with real-time rate to 20 kHz satisfying
IEC 1260-1995 Class 1 and ANSI S1.11-1986 Type 1-D
meeting linearity specifications over a range of 85dB:
- 1/1 octave, 16 Hz to 16 kHz (11 filters)
- 1/3 octave, 12.5 Hz to 20 kHz (33 filters)
• Autom atic logging of sound level parameters including
Interval data, L
statistics, noise event detection using
n
exceedance history and exceedance time history (LOG
only)
• Real-time 1/3 octave spectrum analysis w ith rapid spectrum vs. time autostorage and triggering for sound decay
measurement (RTA)
• Simul taneous operation of sound level meter with independent frequency and 1/3 octave analyzer function
weighting (SSA)
• Advanced time history feature allows you to store up to
38 different parameters including spectral data with each
time history sample
• Narrow band real-time frequency analysis with 400-line
FFT and Hanning window (FFT Mode)
11/8/00 Introduction 1-5
• Standard memory (2 MB) sufficient to store one of the
following:
- 30,000 point 1/3 octave SSA Leq time history
- 20,000 intervals with 1/3 octave Leq spectrum
- 12,300 SSA intervals with Leq & Max 1/3
octave spectra
- 60,000 LOG intervals without Ln
- 35,000 LOG intervals with Ln
- 1,000,000 point time history
- 70,000 RTA 1/1 octave spectra
- 28,000 RTA 1/3 octave spectra
- 2400 FFT 400 line snapshots
• AC/DC output, unweighted, with gain to 50 dB and
attenuation to -20 dB
• Flash memory for in-field firmware upgrades
• Multi-tasking processor: pro vides simultaneous measuring, viewing, transfering and printing of data
• RS-422 (RS-232 compatible) interface:
Serial bit rate to 115 kbps
• Direct report printouts
• Windows
TM
-based software included for setup, control,
and high speed data downloading and translation to
ASCII format
1-6 824 Reference Manual 11/8/00
System 824 Components
38 cm
(15”)
Condenser
Microphone
Preamplifier
LCD Display
Keypad
9 cm
Connectors
(3.5”)
Figure 1-1
The System 824 is a convenient hand-held sound
level meter with a simple user interface.
The standard System 824 shown in Figure 1-1 includes the
following:
• 1/2” diameter condenser microphone
• Backlit graphic 64 x 128 pixel LCD display
• 14-key so ft rubber backlit keypad
• AC/DC output, control, serial, and external power connectors (shown in figure Figure 1-2)
• True “hand held” instrument with “sure grip” pads
11/8/00 Introduction 1-7
AC/DC Output Connector
Control Connector
Serial Interface Connector
External DC Power Connector
Figure 1-2
The System 824 has a series of connectors located at
the bottom of the device consisting of an AC and DC output
connection, control connector, serial interface connector, and
external DC power connector.
The following is a layout of the control connector,which is
used to control external devices and receive external wind
and control information:
12
4
5
Figure 1-3
3
The control connector is a 9 pin mini DIN
6
789
connector.
1 - Ground
2 - Logic output (0 to + 5 volts, active high)
3 - Logic input (0 to + 5 volts, active high)
4 - Wind speed input (.05 to 10 Vdc peak to peak.)
5 - Wind direction A:D input (0 to 5 Vdc)
6 - Wind direction power (+5 Vdc through 250Ω)
7 - Calibration control outp ut (0 to +5 volts, active high, 10
kΩ)
8 - Heater control output (open collector, +40 Vdc Max,
<0.3 Vdc at max 100mA current sink when active low
9 - External power input/output (+8 to +15 Vdc)
1-8 824 Reference Manual 11/8/00
The serial connector is used for computer, printer and
modem communications:
12
4
3
5
8
6
7
Both outputs have a 600 ohm series
resistance.
NOTE: See chapter 5 for more details
concerning the AC/DC outputs.
Figure 1- 4
connector (AppleTalk
The serial connector is an 8 pin mini DIN
TM
compatible pinout).
1 - Flow control output (RS-232C levels)
2 - Flow control input (RS-232C levels)
3 - Transm it data negative ou tput (RS-232C level s)
4 - Ground
5 - Receive data negative input (RS-422)
6 - Transmit data positive output (RS-422)
7 - Control input (RS-232C levels)
8 - Receive data positive input (RS-422)
The AC/DC output connector is used to output the signal
from the System 824 microphone to external devices such as
DAT recorders, real-time analyzers, other sound/vibration
measurement equipment, voltmeters, chart recorders, etc.
AC Output (Tip)
11/8/00 Introduction 1-9
Figure 1- 5
AC/DC output connector
DC Output
Ground (-)
(+)(Ring)
System Diagram
Preamplifier Input Connector
The preamplifier input connector accepts the PRM902
preamp.
Figure 1-6, illustrates the acoustic-to-digital signal path in
the System 824. As you can see, incoming sound is first converted to an electrical signal by the microphone. This electrical signal is filtered and sampled by an analog-to-digital
converter (ADC). The processor then calculates all of the
desired data based on the sampled data (sample rate of 48-
51.2 kHz).
Getting Started
1-10 824 Reference Manual 11/8/00
This section outlines the steps to unpack the System 824.
The following topics are covered:
• Unpacking and Inspection
• Accessories and Optional Equipment
• Connecting Internal or External Power
• Environmental Considerations
AC/DC out
l
AC out
Frequency
Detection
Mux
DC out
AC out
Flat, A-Wt
Digital
Analog to
C-Wt or 10kHz
Signal
Digital
Processor
Converter
C-Wt or 10kHz
Flat, A-Wt
824 System diagram
Analog to
Digital
0-50 dB gain
0-50 dB gain
Converter
Serial I/O
Graphic
Liquid Crystal
Display (LCD)
128x64 with
backlight
RS-422/232
transceiver
Serial I/O
and calendar
Real-time clock
Microprocessor
Flash ROM
RAM
1/2 to 2 MB
Preamplifier
mic
11/8/00 Introduction 1-11
Power
Supply
polarization
Sensor
External
Power
Temperature
Battery
Control I/O
Figure 1-6
Sysjklsfdakjl;fasdjl;kas dflj;ks dfal;jk klj;k
Figdfdsafdsa
System Diagram
Key Pad
Unpacking and Inspection
You will then be ready to use the System 824 for actual measurements.
Your System 824 has been shipped in protective packaging.
Please verify the package contains the items listed below.
Retain the packaging for safe shipmen t for calibration service. Report any damage or shortage immediately to Larson
Davis, Inc. at (801) 375-0177.
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 near the beginning of this manual. You will
find the instrument’s Model/Serial numbers printed on the
label on the instrument’s back panel. The microphone’s
Model/Serial numbers are located on the inside ring of the
microphone. The pre-amplifier’s Model/Serial numbers are
engraved the outside surface. You may be asked to provide
this information during any future communications with
Larson Davis, Inc.
Accessories and Optional Equipment
The 824S is delivered with a 1/2”
microphone, PRM902, WS001 and
does not include the standard accessories.
1-12 824 Reference Manual 11/8/00
The System 824, 824L and 824A are delivered with the following
standard
accessories:
• System 824 instrument
• Model PRM902 microphone preamplifier
• Air condenser microphone
• Battery pack, NiMH, 3.6 V, 1.2 AH (BAT010)
• Alkaline battery terminal assemblies (AM814.06)
nects individual alkaline batteries when NiMH battery pack is
not used.
Con-
• 3” diameter windscreen (WS001) Reduces wind noise
error; protects element from dust and impact.
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