User’s Manual Model 407744 and 407766 Sound Level Calibrators
Introduction Congratulations on your purchase of Extech’s Sound Level Calibrator. Extech Calibrators accommodate Sound Level Meters with a 0.5” microphone. The Calibrator’s die-cast aluminum housing is built for ruggedness and durability. The 407744 provides a 94dB calibration output signal while the 407766 provides both 94dB and 114dB outputs. This professional calibrator, with proper care, will provide years of safe reliable service. Description Note that only the 407766 is pictured. 4 1.
Operation Theory of Operation The 407744 sound level calibrator generates a 94dB sine wave at 1 KHz. The 407766 generates a 94dB and a 114dB sine wave at 1kHz. When a microphone from a sound level meter is inserted into the calibrator, the sound level meter picks up the signal and displays the signal in dB (decibel) units. The sound level meter should be adjusted (if necessary) to match the calibrator’s output signal as closely as possible (see diagram). Procedure 1.
Specifications Output signals 407744: 94dB 407766: 94dB and 114dB Output signal accuracy 407744: ± 0.5dB; 407766: ± 0.5dB (94dB), ±1.0dB (114dB) Output signal frequency 1 KHz sine wave Accuracy of output signal frequency ± 5% Compatible microphones size 0.5” microphones Total Harmonic Distortion (THD) <2%@94dB (407744 and 407766) <5%@114dB (407766) o o Operating temperature 32 to 122 F (0 to 50 C) Power supply Two (2) 9V batteries Power consumption Approx.
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 www.extech.com for contact information.
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 : www.extech.com.
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 www.extech.com para Información de contacto.
