Sound Level Meter ( HTC – SL-1350 )

Description

HTC SL‑1350 Sound Level Meter – High‑Precision Noise Measurement for Professional Use

The HTC SL‑1350 Sound Level Meter is a rugged, user-friendly instrument designed for accurate noise measurement across diverse environments. Built for professionals in industrial compliance, occupational safety, environmental monitoring, building inspection, and acoustical engineering, it delivers dependable sound pressure readings, statistical analysis, and visual alerts with intuitive controls and flexible measurement modes.

High-Accuracy Sound Measurement

Engineered to capture sound pressure levels from 30 dB to 130 dB (A‑weighting) and up to 35 dB to 130 dB with C‑weighting or Flat response, the SL‑1350 offers consistent precision with a fine resolution of 0.1 dB and an accuracy of approximately ±1 dB under calibration conditions. This ensures that even subtle variations in ambient noise can be detected reliably.

Frequency Range and Weighting Options

The meter covers a broad frequency response from 31.5 Hz to 8 kHz, allowing accurate measurement of both low-frequency industrial noise and mid-to-high-frequency urban or workplace sounds. Users can choose between A-weighting, C-weighting, or Flat (F‑weighting) modes, and select Fast (125 ms) or Slow (1 s) time response to suit different testing conditions.

Statistical and Real-Time Sound Metrics

The SL‑1350 supports several advanced sound metrics:

• Lp: real-time instantaneous sound pressure level

• Leq: equivalent continuous sound level over a selectable period

• Lmax and Lmin: highest and lowest levels in a measurement session

• Ln: percentile analysis indicating the percentage of readings above a user-defined threshold (Alarm value)

Alarm Functions and Data Output

The instrument includes adjustable alarm thresholds across the measurement range. The alarm can trigger an LED indication or an optional relay contact output for integration with monitoring systems. It also provides a DC output of 0 to 1.3 V, with 10 mV per dB scaling, enabling data logging via external recording devices or PC confidence software through optional RS‑232 communication.

Display, Controls and Interface

Featuring a 0.4-inch (10 mm) digital LCD display with backlight, the SL‑1350 presents results with clarity and immediacy. Icons on the screen denote weighting mode, response speed, battery status, and alarm conditions. Fast sampling (≈300 ms) ensures updates at least thrice per second for accurate monitoring.

Robust Design and Portability

Measuring approximately 236 × 63 × 26 mm and weighing around 170 g, the unit is compact and easy to carry, providing reliable performance with minimal bulk. It is powered by four AAA (1.5 V) batteries, offering around 60 hours of continuous operation, and features low battery indication along with an auto‑power‑off function configurable for 1–9 minutes of inactivity.

Memory and Measurement Storage

The SL‑1350 stores maximum values for up to 30 groups, allowing verification of peak sound levels during multiple test sessions. These stored data points, along with timestamped sounding conditions, can be transferred to a PC via the optional communication kit for detailed analysis and reporting.

Applications Across Industries

The SL‑1350 is widely used for:

• Industrial noise compliance, monitoring machinery and workplace sound

• Environmental sound surveys, such as traffic noise, construction site checks

• Building inspections in public and commercial environments

• Occupational health, measuring worker exposure levels

• Educational and institutional monitoring, ensuring standards-compliant acoustics

• Equipment testing, measuring and validating sound emissions of devices and appliances.

Key Features at a Glance

• Wide sound measurement range: 30–130 dB (A), 35–130 dB (C/F)

• High resolution and accuracy: 0.1 dB resolution, ±1 dB accuracy

• Frequency response: 31.5 Hz–8 kHz

• Weighting modes: A, C, Flat with Fast/Slow response

• Multiple analysis metrics: Lp, Leq, Lmax, Lmin, Ln (percentile)

• Alarm output: LED indicator, optional relay output

• DC output: 0–1.3 V (10 mV/dB) for data logging

• Communication: Optional RS‑232 interface for PC integration

• Display: Backlit LCD, icons for mode, battery, alarm status

• Power: 4 × AAA batteries, auto power‑off, low battery alert

• Memory: Max value storage for 30 groups

• Size & weight: Compact 236 × 63 × 26 mm; ~170 g

Benefits for Users

This instrument enables professionals to conduct accurate, repeatable measurements of noise levels in compliance-critical settings. Its blend of statistical analysis, clear display, and data output options supports thorough documentation and reporting. Lightweight and easy to use, the SL‑1350 simplifies onsite acoustic testing while offering sophisticated features comparable to higher-end meters.

Conclusion

The HTC SL‑1350 Sound Level Meter is an all‑round, professional-grade solution for precise noise measurement. With advanced response options, statistical features, and flexible output modes, it supports both routine monitoring and detailed acoustic analysis. Whether used for compliance, safety auditing, environmental surveying, or equipment testing, the SL‑1350 delivers reliable performance and data integrity in a portable, easy-to-use form factor.