Sound Calibrator Extech

Extech 407744 and 407766 Sound Level Calibrators

Standard Acoustic Reference Systems with 94 dB and 114 dB Options for Precise Sound Level Meter Calibration in Bioacoustic Research and Environmental Monitoring.

The Extech Sound Level Calibrators (Models 407744 and 407766) are high-precision metrology instruments designed to ensure the accuracy and reliability of sound measurements in environmental monitoring, urban ecology, and bioacoustic research. Accurate calibration is essential for collecting dependable acoustic data from wildlife habitats, natural soundscapes, and industrial environments. These calibrators comply with the IEC 60942:1997-11 international standard, providing a stable and repeatable acoustic reference for demanding field and laboratory applications.

The series includes two models to accommodate different calibration requirements. The Model 407744 produces a fixed 1 kHz sine wave at 94 dB and features a dedicated LED battery status indicator for quick operational checks. The Model 407766 offers greater flexibility through a three-position switch that selects either 94 dB or 114 dB sound pressure levels, making it ideal for calibrating sound level meters used in environments with higher ambient noise. Both models are designed to fit standard 0.5 in (12.7 mm) and 1 in (25.4 mm) microphones, providing a secure acoustic seal for accurate calibration.

Key Features

• Standardized verification and calibration for maximum sound level meter accuracy.
• Compatible with standard 0.5 in (12.7 mm) and 1 in (25.4 mm) acoustic microphones.
• Produces a pure 1 kHz sine wave with less than 2% total harmonic distortion.
• Rugged, portable design with integrated LED indicators for battery monitoring.
• NIST-traceable calibration versions available for scientific, regulatory, and environmental auditing applications.

• Specifications
• In the Box
• Required Items
• Optional Accessories
• Documents

• 	Model 407744	Model 407766
  Frequency	1000 Hz (±5%)
  Sound Pressure Level	94 dB (±0.5 dB)	94 dB / 114 dB (±0.5 dB / ±1.0 dB)
  Total Harmonic Distortion (THD)	<2% at 94 dB
  Operating Temperature	0 to 50 °C (32 to 122 °F)
  Power Supply	Two 9 V Alkaline Batteries
  Power Consumption	Approximately 10 mA DC
  Dimensions	5 cm Diameter × 12.7 cm Length (2.2 × 5.6 in)
  Weight	0.34 kg (340 g / 0.75 lb)

• • 1× Sound Level Calibrator (Selected Model)
  • 2× Heavy-Duty 9 V Alkaline Batteries
  • 1× Calibration Screwdriver
  • 1× Hard Carrying Case

• None: Ready to Use!

• • 407744-NIST: NIST-Traceable Calibration Certification
  • 407766-NIST: NIST-Traceable Calibration Certification
  • Extech Sound Level Meters and Acoustic Measurement Instruments
• • Technical Datasheet (English)