HS5660B High/Low Range Precision Pulse Sound Level Meter

Overview

The HS5660B High/Low Range Precision Pulse Sound Level Meter is a Class 1 compliant portable acoustic measurement instrument engineered for high-fidelity quantification of transient and steady-state sound pressure levels across an exceptionally wide dynamic range. Operating on the fundamental principle of condenser microphone transduction coupled with precision analog signal conditioning and digital signal processing, the HS5660B delivers traceable, repeatable measurements in accordance with IEC 61672-1:2013 and JJG 188–2002 metrological standards. Its dual-range architecture—switchable between low-sensitivity (22–135 dB) and high-sensitivity (55–165 dB) modes—enables accurate characterization of both ultra-quiet environments (e.g., anechoic chambers, quiet rooms per ISO 3745) and high-intensity impulsive sources (e.g., industrial stamping, firearm discharges, pneumatic tool operation). The instrument’s impulse time weighting and true peak detection capability are specifically optimized for capturing short-duration acoustic events with durations as brief as 50 µs, making it suitable for impact noise assessment per ISO 717-1 and building acoustics evaluation under ISO 140-5.

Key Features

• Class 1 accuracy per IEC 61672-1:2013 and JJG 188–2002, validated through factory calibration with NIST-traceable reference microphones
• Dual-range operational mode: selectable low-range (22–135 dB) and high-range (55–165 dB) configurations for extended dynamic coverage without manual attenuation
• Three frequency weightings—A, C, and Linear (F)—supporting regulatory compliance (e.g., OSHA 1910.95, EU Directive 2003/10/EC) and research-grade spectral analysis
• True RMS and peak detectors with simultaneous readout, enabling simultaneous assessment of energy-equivalent (Leq) and maximum instantaneous pressure (Lpk)
• Impulse time weighting (I-time constant: 35 ms ± 10%) for standardized evaluation of impact sound insulation (ISO 140-7) and occupational impulse noise exposure
• Integrated 1000 Hz sine-wave calibrator (±0.2 dB tolerance) for on-site functional verification prior to and after measurement sessions
• Simultaneous analog AC and DC output ports (BNC) for real-time connection to oscilloscopes, data loggers, or external octave band analyzers such as the HS5721 (1/1-octave) or HS5731 (1/3-octave) filter sets
• Robust mechanical design: compact housing (290 × 106 × 65 mm), IP54-rated ingress protection against dust and water splashes, and integrated windscreen mount for outdoor field use

Sample Compatibility & Compliance

The HS5660B is compatible with standard 1/2-inch externally polarized condenser microphones (IEC 61094-4 Type WS2F or equivalent), including those equipped with preamplifiers meeting IEC 61094-7 requirements. It supports direct coupling with calibrated pistonphones (e.g., Brüel & Kjær Type 4228) for primary acoustic calibration. The device meets the essential requirements of the EU Measuring Instruments Directive (MID 2014/32/EU) for sound level meters and is designed to support GLP-compliant workflows through documented calibration history, operator identification fields, and timestamped measurement logging. All firmware and hardware configurations adhere to electromagnetic compatibility (EMC) requirements per EN 61326-1:2013 and safety standards per EN 61010-1:2010.

Software & Data Management

While the HS5660B operates as a standalone meter with dual LCD + analog needle display for immediate visual feedback, its analog outputs enable seamless integration into PC-based acquisition systems using industry-standard DAQ hardware (e.g., National Instruments USB-4431, Dewesoft SIRIUS). Raw voltage signals from the AC output can be post-processed in MATLAB, Python (SciPy/NumPy), or dedicated acoustics software (e.g., HEAD Acoustics ArtemiS SUITE, Siemens Simcenter Testlab) for FFT-based spectral decomposition, statistical analysis (L₁₀, L₅₀, L₉₀), and time-history reconstruction. Internal memory is not included; however, external recording is supported via synchronized trigger signals and calibrated gain settings. For auditability, users are advised to maintain calibration certificates, microphone sensitivity records, and environmental condition logs (temperature, humidity, atmospheric pressure) per ISO/IEC 17025:2017 clause 7.7.

Applications

• Environmental noise monitoring near airports, highways, and industrial perimeters (ISO 1996-1 & ISO 1996-2)
• Occupational health and safety assessments in manufacturing, construction, and defense sectors (NIOSH REL, ACGIH TLV)
• Building acoustics testing—including impact sound pressure level (L’nT,w) determination per ISO 140-7 and airborne sound insulation (R’w) per ISO 140-3
• Product noise certification for household appliances, power tools, and HVAC equipment (IEC 60704, ISO 3744)
• Acoustic validation of hearing protection devices (HPDs) in laboratory and field settings (ANSI S12.6)
• Educational laboratory instruction in acoustics, vibration, and signal processing curricula

FAQ

Does the HS5660B meet international Class 1 requirements?
Yes—it complies fully with IEC 61672-1:2013 Class 1 specifications and is verified against JJG 188–2002, China’s national metrological verification regulation for sound level meters.
Can the HS5660B be used for legal noise enforcement?
It is suitable for regulatory monitoring where Class 1 instrumentation is mandated, provided that periodic calibration by an ISO/IEC 17025-accredited laboratory is maintained and documented.
Is external power required for continuous field operation?
No—the unit operates on four 1.5 V alkaline cells (approx. 20 hours runtime), but an optional 220 V AC/DC adapter is available for extended stationary deployments.
What accessories are recommended for outdoor measurements?
A certified windscreen (included), tripod mounting kit, extension cables (10 m/15 m/30 m), and a portable pistonphone calibrator (e.g., HS6020) are strongly advised for meteorological compensation and traceability.
How is traceability established for measurement data?
Traceability is maintained through documented calibration certificates (including microphone sensitivity, preamplifier gain, and system response curves), all referenced to national standards (e.g., NIM China, PTB Germany, or NPL UK).