TES-1350A Digital Sound Level Meter

Overview

The TES-1350A Digital Sound Level Meter is a portable, handheld acoustic measurement instrument engineered for precision environmental noise assessment and occupational health & safety compliance. It operates on the principle of electret condenser microphone transduction coupled with analog-to-digital signal conditioning and real-time weighting filter implementation (A- and C-weighting per IEC 651:1979 Class 2 specifications). Designed for field-deployable use in industrial hygiene surveys, community noise mapping, facility maintenance audits, and regulatory pre-screening, the device delivers stable, repeatable sound pressure level (SPL) readings across a broad dynamic range. Its compact form factor, low power consumption, and intuitive single-button operation support extended battery-powered operation without compromising metrological integrity under typical ambient conditions.

Key Features

• True RMS detection circuitry with dual-range measurement capability: Low range (35–100 dB) and High range (65–130 dB) for both A- and C-frequency weightings
• High-resolution 3½-digit LCD display with 0.1 dB resolution and automatic decimal point positioning
• Simultaneous support for Fast (125 ms) and Slow (1 s) time-weighted response modes per IEC 651
• Maximum Hold function with auto-locking peak value retention and decay rate < 1 dB/3 min for transient event capture
• Integrated 94.0 dB @ 1 kHz internal electroacoustic calibration source—no external calibrator required for daily functional verification
• Dual-output interface: AC line-level output (~0.65 Vrms, 600 Ω impedance) for connection to chart recorders or data loggers; DC output (10 mV/dB nominal, 100 Ω impedance) for analog integration into SCADA or PLC systems
• Robust mechanical architecture: ABS housing, integrated windscreen-compatible design, and ergonomic grip optimized for one-handed operation

Sample Compatibility & Compliance

The TES-1350A is validated for use with standard 1/2-inch electret condenser microphones conforming to IEC 61094-4 requirements. It meets IEC 651:1979 Type 2 performance criteria for general-purpose sound level meters—including frequency response flatness (±2 dB tolerance from 31.5 Hz to 8 kHz), linearity error (< ±0.5 dB over 65 dB dynamic span), and temperature/humidity stability within operational limits (0–40 °C, <80% RH). While not certified to ANSI S1.4-2014 Type 2 or IEC 61672-1:2013 Class 2, its metrological behavior aligns with baseline expectations for screening-grade measurements in non-critical applications. It supports documentation workflows compliant with OSHA 1910.95, ISO 1996-2:2017 (acoustics — description, measurement and assessment of environmental noise), and EU Directive 2002/49/EC (Environmental Noise Directive) preliminary survey protocols.

Software & Data Management

The TES-1350A operates as a standalone analog/digital hybrid meter with no embedded firmware-based data logging. However, its analog outputs enable seamless integration with third-party acquisition systems supporting voltage-to-decibel conversion (e.g., National Instruments DAQmx, LabVIEW-based noise analysis modules, or custom Python/Arduino ADC interfaces). When paired with calibrated recording equipment, it satisfies basic GLP traceability requirements through manual entry of calibration date, operator ID, and environmental conditions into lab notebooks or LIMS platforms. The device does not implement FDA 21 CFR Part 11 electronic signature or audit trail functionality, nor does it feature Bluetooth/Wi-Fi connectivity—making it suitable for environments where electromagnetic interference mitigation or air-gapped instrumentation is mandated.

Applications

• Workplace noise exposure screening per OSHA PEL and NIOSH REL thresholds
• Pre-commissioning acoustic checks in HVAC, manufacturing, and transportation infrastructure projects
• Community noise monitoring near construction sites, airports, and rail corridors
• Educational laboratory demonstrations of sound wave propagation, attenuation, and frequency weighting effects
• Facility maintenance diagnostics—including fan, pump, and compressor vibration-induced airborne noise characterization
• Baseline environmental impact assessments prior to EIA submission

FAQ

What standards does the TES-1350A comply with?
It conforms to IEC 651:1979 Type 2 specifications for general-purpose sound level meters.
Can this meter be used for legal noise enforcement?
No—it is intended for screening and indicative measurements only; formal regulatory enforcement requires IEC 61672-1 Class 1 or Class 2 certified instruments.
Is external calibration required before each use?
No—internal 94.0 dB calibration at 1 kHz enables rapid functional verification; however, annual traceable calibration against an accredited acoustic standard is recommended for quality assurance.
Does the device support data logging?
Not natively—the unit lacks onboard memory or digital communication ports; external analog recording is required for time-series capture.
What is the expected battery life?
Approximately 100 hours of continuous operation using a standard 9 V alkaline battery under typical load conditions.