ST-21D Class 2 Sound Level Meter
ST-21D Class 2 Sound Level Meter
ST-21D Sound Level Meter meets the Class 2 IEC 61672:2013 standard, making it ideal for general environmental noise measurements. It calculates continuous sound levels and exposure over a set period, ensuring compliance with OSHA and Noise at Work regulations to protect employee hearing and safety.
Technical Specifications
ST-12D Class 1 Integrating SLM
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The sensor supports real-time data acquisition and seamless integration with CAN bus and data logging systems. With its robust construction, low latency, and high resolution, SV 977D is ideal for automotive testing, braking analysis, and vehicle dynamics evaluation.
Key Features
- IEC 61672-1:2013 Class 2 compliant for reliable noise measurement
- Wide measurement range of 28 dB to 133 dB
- High accuracy up to ±0.7 dB with 0.1 dB resolution
- Frequency range from 20 Hz to 12.5 kHz
- A, C and Z frequency weightings
- Fast, Slow, Impulse and Peak time weightings
- Data logging and recording functionality
- RS232 and USB data output for PC connectivity
- Measurement report generation and printing support
- 128 × 64 OLED display for clear data visualization
Applications
Vehicle speed and performance testing
Brake testing and stopping distance analysis
Automotive research and development (R&D)
Vehicle dynamics and motion analysis
ADAS and safety system validation
Testing in varying road and weather conditions
Real-world driving data collection
Integration with CAN-based systems for diagnostics
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Fulfils standard
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Main parameters of measurement
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Measurement range
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Measurement level
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Frequency range
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Display
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Weight
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Application
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Power Supply
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IEC 61672:2013 Class 2
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28dB to 133dB wide measurement range
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Data Logging
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RS232 & USB Data Output
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Leq value with A/C/Z/B frequency weightings
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Why Choose ST-21D?
Designed for environmental & occupational noise measurements
High Precision
IEC 61672:2013 Class 2 standard with high accuracy of ±0.7 dB
Smart Integration
Measures and displays Leq value with adjustable A/C/Z frequency weightings
Built-in Datalogger
Download raw data directly to your computer using a USB cable
Data Transfer to Windows PC
Transfers data to a Windows PC via USB cable and stores up to 8,000 sets of measurement results, including timestamp, % dose, and TWA.
Quality Assurance & Packaging
Every ST-21D is rigorously tested for quality before shipping and securely packed in a cardboard hand carry case to protect its components. This ensures your sound level meter arrives in perfect condition, ready for use.
Have Questions? Get in Touch
What is the ST-21D Class 2 Sound Level Meter and where is it used?
ST-21D Class 2 Sound Level Meter is a professional acoustic measurement instrument designed for environmental noise monitoring, workplace safety assessments, and general industrial noise measurement. It is widely used in construction, automotive, and occupational health applications.
What does “Class 2” mean for the ST-21D?
Class 2 indicates compliance with IEC 61672:2013, providing reliable accuracy for general-purpose noise measurements. It offers ±0.7 dB accuracy, making it suitable for industrial, environmental, and workplace noise assessments where Class 1 certification is not mandatory.
What are the key measurement capabilities of the ST-21D?
The ST-21D measures a wide range of acoustic parameters including:
- Leq (equivalent continuous sound level)
- SEL, Lmax, Lmin, Peak levels
TWA, %Dose, and statistical values (Ln)
It supports A, C, Z frequency weightings and Fast, Slow, Impulse, and Peak time weightings, enabling comprehensive noise analysis.
What is the measurement range and frequency range of ST-21D?
The device offers a measurement range of 28 dB to 133 dB (up to 145 dB peak) and a frequency range of 20 Hz to 12.5 kHz, making it suitable for both low-level environmental noise and high-intensity industrial noise applications.
What features make ST-21D suitable for field and industrial use?
Key features include:
- Built-in data logger (stores up to ~8000 records)
- USB and RS232 connectivity for data transfer
- OLED display for easy operation
- Portable, lightweight design (~0.4 kg)
- Capability to function as sound level meter, dosimeter, and data logger
These features make it ideal for long-term monitoring and compliance reporting.