Professional Sound Level Meters with Built-In Data Logging

IEC61672-2002 class I accuracy. Weatherproof, WiFi-enabled, cloud-connected instruments for environmental monitoring, workplace safety & acoustic research. Starting at 296 USD.

IEC61672-2002 class I accuracy Weatherproof WiFi & Cloud Made in Canada
Starting At
$296 USD
Noise Floor
29 dBA
4 Models
USB · WiFi · Cloud · Dev
Calibration Certificate Included
Free Software & Updates
Direct Manufacturer Support
Shipping Worldwide

Which model to choose?

Feature NSRT_mk4 NSRTW_mk4 NSRTW_mk4 Cloud
Price Base price (no WiFi) Higher (adds WiFi) Highest (WiFi + Cloud service)
Battery Life 5 to 7 days on battery, months while externally powered Similar autonomy on battery, WiFi reduces battery time. Similar autonomy on battery, WiFi reduces battery time
WiFi Built-in No Yes Yes
24/7 Cloud No Optional / via local setup Yes, 1Y included
Best For Short-term logging with local download WiFi projects with local IT / VPN Remote 24/7 cloud noise monitoring

Everything You Need to Know About Sound Level Meters

Choosing the right sound level meter depends on your monitoring duration, connectivity needs, and application.

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Our engineers can help you select the right model for your application.

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What is a sound level meter and how does it work? +
A sound level meter (also called a decibel meter, noise meter, or SPL meter) is a precision instrument that measures sound pressure levels in decibels (dB). It uses a calibrated microphone to convert acoustic pressure waves into electrical signals. Professional sound level meters like the Convergence Instruments NSRT series use Class 1 MEMS microphones for high accuracy and long-term stability, with A, C, and Z frequency weighting filters.
What's the difference between Class 1 and Class 2 sound level meters? +
Class 1 and Class 2 refer to IEC 61672 accuracy standards. Class 1 offers tighter tolerances and wider frequency range (16 Hz to 16 kHz), suitable for professional, regulatory, and research use. Class 2 has wider tolerances for general-purpose surveys. All our NSRT models comply with the accuracy requirements of the IEC61672-2002 class 1 standard. They do not comply with all the requirements. For instance the microphone is digital at the chip level, so they cannot support electrical testing.
Can I use a smartphone app instead of a dedicated sound level meter? +
Smartphone apps give rough estimates but lack the precision for professional use. Microphone quality, phone shape, calibration, and environment all affect accuracy. Phones also can't be left on-site for extended periods. For regulatory compliance, environmental studies, or OSHA monitoring, a calibrated Class 1 sound level meter is required.
How long can Convergence sound level meters record continuously? +
On internal battery, approximately one week. With an external USB charger or solar panel accessory, months without interruption. The NSRTW_mk4 with cloud reports data automatically via WiFi at preset intervals for truly unattended long-term monitoring.
Do I need WiFi and cloud connectivity? +
For short-term surveys (days to weeks), the NSRT_mk4 with USB is sufficient and more affordable. For remote multi-site monitoring over months with real-time alerts, the WiFi-enabled NSRTW_mk4 saves travel time and labor. The cloud option adds browser-based access from anywhere, multi-user management, and over-the-air reconfiguration.
What metrics do these sound level meters measure? +
All models record Leq, Lmax, Lmin, Lpeak. Log intervals range from 125 ms (8 values/sec) to hours. Free software calculates CNEL, Lden, percentiles (L10, L50, L90), and includes oscilloscope and spectrum analyzer functions.
Are these meters suitable for outdoor use? +
Yes. Every NSRT model features a completely sealed weatherproof enclosure with an ePTFE membrane protecting the microphone against dust and water when mounted according to instructions. Optional windscreens and various mounting options (magnetic, tripod, wall mount) are available for any installation scenario.

Sound Level Meter Buyer's Guide

How to choose your sound level meter

How to Choose Your Sound Level Meter

Choosing the right sound level meter depends on your specific requirements. Are you monitoring environmental noise, occupational noise, or conducting scientific studies? Consider the accuracy, cost, datalogging, recording time, and additional features like weather-resistance or wireless connectivity. Our sound level meters offer various options to meet these diverse needs.

Applications of a Sound Level Meter

Sound level meters are vital tools in numerous fields. They ensure compliance with local noise regulations in environmental noise monitoring and protect workers' hearing in workplace noise monitoring. Additionally, they are invaluable in research for measuring sound levels across different environments. Our products excel in these diverse applications.

Features of a Sound Level Meter

Modern sound level meters come with advanced features. Look for models with selectable frequency weightings (A, C, or Z) for precise measurements tailored to different applications. Data logging capabilities enable continuous monitoring and recording of sound levels over time. Wireless and cloud connectivity, such as WiFi, add convenience for remote monitoring. Our meters include these features to enhance your noise measurement experience.

Types of Sound Level Meter

Sound level meters vary based on functionality and application. Basic models measure instantaneous sound pressure levels while integrating models provide levels averaged over time (LEQ). Data logging meters store measurements for later analysis. All our sound level meters are integrating models.

Classes of Sound Level Meter

Sound level meters are primarily classified as Class 1 and Class 2. Class 1 offers high precision and a wide frequency range, making them suitable for professional and research purposes. Class 2 have slightly wider tolerances and are aimed at less demanding applications. All of our NSRT series comply with the precision requirements of IEC61672-2002 Class 1 and come with factory calibration certificates to insure the accuracy you need.

How to Choose the Right Sound Level Meter for Your Needs

Understanding your specific needs is key to choosing the right sound level meter. For short-term (up to a few weeks) operation, choose the simple low-cost NSRT_mk4. For operations spanning multiple months, and to avoid having to dispatch personnel to the location(s), choose the NSRTW_mk4 or NSRTW_mk4 with cloud. For OEMs and developers wanting to integrate the instrument to their own system, choose the NSRT_mk4_Dev, and if you need an open wireless protocol to integrate the instrument to your own cloud service, choose the NSRTW_mk4_MQTT.

How Accurate Is a Smartphone Sound Meter App?

Sound meter apps on smartphones can provide a rough estimate of noise levels but lack the precision and reliability of dedicated sound level meters. Factors like shape, size, microphone quality and calibration, and environmental conditions can affect their accuracy. In addition, a smart phone usually cannot be left on location for extended periods of time. For professional and regulatory purposes, it's best to use a calibrated sound level meter. Our meters provide the accuracy you need.

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