Manual - Extech Instruments

User's Manual
Digital Sound Level Meter
Model 407768
Congratulations on your purchase of the Extech 407768 Sound Level Meter. This Auto Range
Sound Level Meter meets ANSI and IEC Type II accuracy standards. Professional features
include programmable Frequency Weighting and Time Response, Min/Max Memory, Max Hold,
Analog output, and RS-232 PC Interface. This meter is shipped fully tested and calibrated and,
with proper use, will provide years of reliable service.
5 Digit LCD with overload, low battery and multifunction
Frequency bandwidth
31.5 Hz to 8 KHz
0.5” Electret Condensor Microphone
Output terminals
Optically isolated RS-232 port and AC output
Measurement ranges
Auto Range: 30 to 130dB
Manual Ranges: 30 to 80dB, 50 to 100dB, 80 to 130dB
Frequency weighting
‘A’ and ‘C’ (Programmable)
Applicable standards
ANSI S1.4:1983 Type 2, / IEC 61672 Class 2,
Maximum/Minimum record
Highest and lowest readings are stored for later recall
Data Hold
Displayed reading is held when HOLD key is pressed
Max Hold
Highest reading displayed only
Response time
Fast: 125ms / Slow:1s (Programmable)
AC Analog output
0.5VAC rms full scale (600 output impedance)
9V Battery; Consumption: 6mADC approx.
Operating temperature
32 to 122 F (0 to 50 C)
Operating humidity
Less than 80% RH
Dimensions / Weight
10.6 x 2.7 x 1.1" / 0.63 lbs. (268 x 68 x 29mm / 285g)
Meter Description
LCD Display
Power, Hold, and Min/Max buttons
Max, Weighting, Response Time, & Range buttons
AC output jack
Calibration potentiometer
RS-232 PC interface jack
Battery compartment, tilt stand,
and tripod mount on rear
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Sound Level Meter Operation
Meter Power
1. The meter is powered by a 9V battery. The battery compartment is located on the rear of the
meter and the compartment cover is secured by one Phillips screw. When the battery icon
appears on the top left corner of the meter's display, replace the battery.
2. Press the POWER button to turn the meter on. Note that the Meter is equipped with an Auto
Power Off feature that shuts the meter off after 10 minutes. To defeat Auto Power Off, put the
meter in Record mode by pressing the REC MAX/MIN button.
3. Press the POWER button to turn the meter off.
Default Configuration
1. The meter's default configuration is as follows: Auto Range, 'A' Frequency Weighting, and
'FAST' Response Time
2. The lower portion of the LCD will reflect the meter's configuration, i.e., 'A', 'Fast', 'Auto'.
Measurement Considerations
1. Use a windscreen (not included) to cover the microphone in windy conditions.
2. Calibrate the meter often, especially if the meter has been idle for a long period of time.
3. Do not store/operate the meter in areas of high temperature or humidity.
4. Keep the meter and the microphone dry.
5. Avoid severe vibration when using the meter.
6. Remove the battery when the meter will be stored for long periods of time.
Frequency Weighting
Change the Frequency Weighting by pressing the 'A/C' button. The 'A' or 'C' icon will display on the
lower left-hand area of the LCD.
Note: With ‘A’ weighting selected, the meter responds like the human ear (boosting and cutting the
noise amplitude over the frequency spectrum - see Appendix). ‘A’ weighting is used for
environmental measurements, OSHA regulatory testing, law enforcement, and workplace design.
Select ‘C’ weighting for flat response measurements (no boost or cut). ‘C’ weighting is suitable for
the sound level analysis of machines, engines, etc. Most OSHA related testing is performed using
'A' Weighting and SLOW Response Time settings.
Response Time
Change the Response Time by pressing the 'FAST/SLOW' button. The 'FAST' or 'SLOW' icon will
display on the lower left-hand area of the LCD.
Note: Select FAST to capture noise peaks and noises that occur very quickly. Select the SLOW
Mode to monitor a sound source that has a reasonably consistent noise level or to average quickly
changing levels. Selection of Fast or Slow is determined by the application and any directives or
standards related to that application.
Auto/Manual Range
Press the RANGE button to scroll through the following ranges: Auto, 30-80dB, 50-100dB, and 80130dB. The display will reflect the range for each button press.
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The Sound Level meter should be calibrated before each use; an external sound level meter
calibrator is required. Set the meter to the Manual range (50-100dB), FAST response and ‘A’
weighting before starting.
1. Place the external calibrator over the Sound Level Meter's microphone and turn the Calibrator
2. The meter should read close to, or exactly, the calibrator's dB output level. Typical Calibrator
output levels are 94dB and 114dB.
3. If the meter is within ± 0.2 dB of the calibrator’s output, no adjustment is necessary.
4. Adjust the calibration pot in the output/calibration compartment if necessary to bring the meter
display in line with the calibrator output signal.
Taking Measurements
1. Hold the meter in hand, place it on a desktop (using the rear tilt stand), or mount it on a tripod
using the tripod mount on the rear of the meter.
2. Point the microphone toward the source of noise/sound to be measured.
3. Read the measurement, in dB units, on the LCD display.
Data Hold
1. Press the HOLD button to freeze the displayed reading. The LCD will display the icon HOLD
when Data Hold is engaged.
2. Press the HOLD button to de-activate this feature. The HOLD icon will extinguish.
3. Note that Data Hold is not available while the meter is in the Max/Min Record mode.
Max Hold
1. Press the MAX HOLD button to activate this feature. The LCD will display PH when Max Hold is
2. The meter will now display only the highest reading. Each time a higher reading is encountered
the display will update.
3. Press the MAX HOLD button again to de-activate this feature. The PH icon will extinguish.
4. Note that Max Hold is not available while the meter is in the Max/Min Record mode.
Max/Min Data Recording
The Max/Min feature stores the maximum reading and minimum reading while the user takes
measurements. The Max and the Min readings can later be recalled.
1. Press the REC MAX/MIN button to activate this feature. The LCD will display the icon REC and
the meter will begin monitoring the highest (Max) and lowest (Min) readings.
2. After measurements are made, press the REC button again to view the Max reading. The MAX
icon will appear on the LCD along with the highest reading.
3. Press the REC to view the minimum (MIN) reading. The 'MIN' display icon will appear on the
LCD along with the lowest reading.
4. To exit this mode, press and hold the REC button until the REC indicator extinguishes.
5. To clear a Max or Min reading, press the HOLD key while viewing either the MAX or MIN value.
Note that exiting the Record mode also clears the MAX and MIN values.
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Analog Output
The AC analog output transmits 0.5V AC rms full scale. The output impedance is 600maximum.
The mono 3.5mm mini-jack is located in the output/calibration compartment on the right side of the
instrument. Use a phono plug (3.5mm mono) to connect to the output jack.
PC Interface
The optically isolated RS-232 PC Interface port is located in the output/calibration compartment
situated on the lower right side of the meter. The supplied Data Acquisition Software package
includes Windows 95 / 98 / NT / 2000 / XP compatible software and a meter-to-PC interface
cable. Instructions for use can be found on the included software CD.
Important Note on the Automatic Power OFF feature
The 407768 Sound Level Meter has an AUTO POWER OFF feature that turns the meter off after
approximately 10 minutes. This feature must be disabled before starting a datalogging session to
avoid having the meter automatically shut off in the middle of a session. Disable it by pressing the
REC MAX/MIN button to activate the Record mode. While the meter is in the Record mode, the
AUTO POWER OFF feature is disabled.
Battery Replacement
The 9V battery that powers the Sound Level Meter is housed in the rear battery compartment. When
the battery icon appears on the top left corner of the meter's LCD, it is time to replace the battery.
1. Open the battery compartment by first removing the Phillips screw and then sliding the
compartment cover down and off.
2. Replace the 9V battery, slide the cover on, and replace the screw.
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Warranty FLIR Systems, Inc. warrants this Extech Instruments brand device to be free of defects in parts and workmanship for one year from date of shipment (a six month limited warranty applies to sensors and cables). If it should become necessary to return the instrument for service during or beyond the warranty period, contact the Customer Service Department for authorization. Visit the website for contact information. A Return Authorization (RA) number must be issued before any product is returned. The sender is responsible for shipping charges, freight, insurance and proper packaging to prevent damage in transit. This warranty does not apply to defects resulting from action of the user such as misuse, improper wiring, operation outside of specification, improper maintenance or repair, or unauthorized modification. FLIR Systems, Inc. specifically disclaims any implied warranties or merchantability or fitness for a specific purpose and will not be liable for any direct, indirect, incidental or consequential damages. FLIR’s total liability is limited to repair or replacement of the product. The warranty set forth above is inclusive and no other warranty, whether written or oral, is expressed or implied. Calibration, Repair, and Customer Care Services FLIR Systems, Inc. offers repair and calibration services for the Extech Instruments products we sell. NIST certification for most products is also provided. Call the Customer Service Department for information on calibration services available for this product. Annual calibrations should be performed to verify meter performance and accuracy. Technical support and general customer service is also provided, refer to the contact information provided below. Support Lines: U.S. (877) 439‐8324; International: +1 (603) 324‐7800 Technical Support: Option 3; E‐mail: [email protected] Repair & Returns: Option 4; E‐mail: [email protected] Product specifications are subject to change without notice Please visit our website for the most up‐to‐date information FLIR Commercial Systems, Inc., 9 Townsend West, Nashua, NH 03063 USA ISO 9001 Certified Copyright © 2013 FLIR Systems, Inc. All rights reserved including the right of reproduction in whole or in part in any form
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Garantie FLIR Systems, Inc. garantit que cet appareil Extech Instruments est exempt de défauts matériaux et de fabrication pendant un an à partir de la date d’envoi (une garantie limitée de six mois s’applique aux capteurs et aux câbles). Si le renvoi de l’appareil pour réparation devient nécessaire durant ou après la période de garantie, contactez le service client pour autorisation. Pour obtenir les coordonnées, visitez le site Web suivant : Un numéro d’autorisation de retour (AR) doit être délivré avant tout retour de produit. L’expéditeur prend à sa charge les frais d’expédition, le fret, l’assurance et l’emballage correct de l’appareil afin de prévenir toute détérioration durant le transport. Cette garantie ne s’applique pas aux dommages imputables à l’utilisateur, tels que l’usage impropre ou abusif, un mauvais câblage, une utilisation non conforme aux spécifications, un entretien ou une réparation incorrecte, ou toute modification non autorisée. FLIR Systems, Inc. déclinera spécifiquement toute garantie ou qualité marchande ou aptitude à l’emploi prévu, et ne sera en aucun cas tenu responsable pour tout dommage conséquent, direct, indirect ou accidentel. La responsabilité totale de FLIR est limitée à la réparation ou au remplacement du produit. La garantie définie ci‐dessus est inclusive et aucune autre garantie, écrite ou orale, n’est exprimée ou implicite.
Calibrage, réparation et services après‐vente FLIR Systems, Inc. offre des services de calibrage et de réparation pour les produits Extech Instruments que nous commercialisons. Nous fournissons également une certification NIST pour la plupart des produits. Contactez notre service client pour toute information sur les services de calibrage disponibles pour ce produit. Un calibrage doit être effectué chaque année pour vérifier les performances et la précision du mètre. Nous offrons également une assistance technique et un service à la clientèle. Veuillez vous reporter aux coordonnées fournies ci‐dessous. Lignes d’assistance: États‐Unis (877) 439‐8324; international: +1 (603) 324‐7800 Service d’assistance technique : Option 3 ; E‐mail : [email protected] Réparations et retours : Option 4 ; E‐mail : [email protected] Les spécifications produit sont sujettes à modifications sans préavis. Pour les toutes dernières informations, veuillez visiter notre site Web. FLIR Commercial Systems, Inc., 9 Townsend West, Nashua, NH 03063 USA Certifié ISO 9001 Copyright © 2013 FLIR Systems, Inc. Tous droits réservés, y compris la reproduction partielle ou totale sous quelque forme que ce soit. 7
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Garantía FLIR Systems, Inc., garantiza este dispositivo marca Extech Instruments para estar libre de defectos en partes o mano de obra durante un año a partir de la fecha de embarque (se aplica una garantía limitada de seis meses para cables y sensores). Si fuera necesario regresar el instrumento para servicio durante o después del periodo de garantía, llame al Departamento de Servicio a Clientes para obtener autorización. Visite para Información de contacto. Se debe expedir un número de Autorización de Devolución (AD) antes de regresar cualquier producto. El remitente es responsable de los gastos de embarque, flete, seguro y empaque apropiado para prevenir daños en tránsito. Esta garantía no se aplica a defectos resultantes de las acciones del usuario como el mal uso, alambrado equivocado, operación fuera de las especificaciones, mantenimiento o reparación inadecuada o modificación no autorizada. FLIR Systems, Inc., rechaza específicamente cualesquier garantías implícitas o factibilidad de comercialización o idoneidad para cualquier propósito determinado y no será responsable por cualesquier daños directos, indirectos, incidentales o consecuentes. La responsabilidad total de FLIR está limitada a la reparación o reemplazo del producto. La garantía precedente es inclusiva y no hay otra garantía ya sea escrita u oral, expresa o implícita. Servicios de calibración, reparación y atención a clientes FLIR Systems, Inc., ofrece servicios de reparación y calibración para los productos que vendemos de Extech Instruments. Además ofrecemos certificación NIST para la mayoría de los productos. Llame al Departamento de Servicio al Cliente para solicitar información de calibración para este producto. Para verificar el funcionamiento y precisión se debe realizar la calibración anual. Además se provee Soporte Técnico y servicios generales al cliente, consulte la información de contacto en seguida. Líneas de soporte: EE.UU. (877) 439‐8324; Internacional: +1 (603) 324‐7800 Soporte Técnico Opción 3; correo electrónico: [email protected] Reparación / Devoluciones: Opción 4; correo electrónico: [email protected] Las especificaciones del producto están sujetas a cambios sin aviso Por favor visite nuestra página en Internet para la información más actualizada FLIR Commercial Systems, Inc., 9 Townsend West, Nashua, NH 03063 USA Certificado ISO 9001 Copyright © 2013 FLIR Systems, Inc. Reservados todos los derechos, incluyendo el derecho de reproducción total o parcial en cualquier medio
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Typical 'A' Weighted dB levels
50 HP Siren (100')
Jet take-off (200')
Riveting machine
Chain saw
Subway (20')
Boiler room
Pneumatic drill (50')
Vacuum cleaner (10')
Freight train (100')
Speech (1')
Large Office
Large store
Small office
Residential area
Sound studio
Whisper (5')
Threshold of hearing
Frequency Weighting Graph
dB (relative)
Frequency Weighting
'A' Weighting
'C' Weighting
Frequency (Hz)
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