Types of sound level meters

Types of sound level meters

What are the different types of sound level meters?

  • Class 1 Sound Level Meters: the most precise and most expensive sound level meter, meeting IEC 61672-1 standard and having a type approval
  • Class 2 Sound Level Meter: a less accurate and less expensive sound level meter that meets IEC 61672-1 standard
  • Low-cost sound meters which do not conform to IEC 61672, usually sold in markets

What is a sound level meter?

Sound level meter is an instruments for measuring sounds in the audible range.It is generally composed of a microphone, a preamplifier, a signal processor, and a display that displays noise results. 

Hand-held sound level meters are usually battery-powered and feature a triangular tip and around windscreen on top. Sound level meters are also known as sonometers or decibel meters but these generic names frequently apply to non-professional sound measurement devices that do not meet the IEC 61672 requirements.

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What is the best sound level meter for me?

It can be a challenge to find the right sound level meter for your specific needs. First, you must decide how the sound level meter will be used. Typically, professional noise measurements follow standardized procedures that provide requirements for the type of sound meter. If you need to measure noise for your interests, a mobile application is just as good as purchasing a market sound level meter.

Noise measurement applications

The following are the most common types of professional sound measuring applications:

  • occupational noise
  • environmental noise
  • building acoustics and room acoustics
  • and various engineering sound measurements.

Types of pro sound level meters

There are two main types of pro sound level meters:

  • Class 1 sound level meters

These are the most accurate and expensive types of noise meters. They are typically used in professional noise measurements such as environmental noise, building acoustics, engineering measurements, or sound power.

  • Class 2 sound level meters

These are less expensive and still provide accurate noise measurements. Class 2 sound level meters are typically used in environments such as office noise, classroom noise, or general industrial noise.

Types of sound level meters for occupational noise measurements

Unless otherwise indicated in the measurement standard, class 2 sound level meters are generally accepted for noise surveys at work.

What is the difference between Class 1 and Class 2?

Class 1 sound level meters are more accurate and more expensive than Class 2 sound level meters, which are less accurate but still provide exact noise readings. You can read more about their differences in the next section of this article.

How do I choose the right sound level meter for my needs?

There are a few factors to consider when choosing a sound level meter:

  • What type of noise environment will you be measuring?

If you’re measuring environmental noise, you’ll need a Class 1 sound level meter. For industrial noise measurements, you’ll probably use a Class 2 sound level meter.

  • What range of noise levels do you need to measure?

Most sound level meters have a range of 30-130 dB. The range that you need depends on the object you are measuring. For environmental noise measurements, you may need a lower range than 25 dB but not necessarily up to 140 dB. In the case of industrial noise, you will need the upper level to be at least 140 dB.

  • What is your budget for a sound level meter?

Class 1 meters are more expensive than Class 2, but both will give you accurate noise measurements as long as they meet the requirements of the IEC 61672-1 standard.

IEC 61672 Sound Level Meters

The IEC 61672-1 is an international standard that specifies the performance criteria for professional sound level meters. There are two performance categories specified by this standard: class 1 and class 2.

The following are the most essential components for sound level meters that comply with this standard:

  • linear operating range
  • frequency response
  • and temperature operating range

What's the difference between IEC 61672 Class 1 and Class 2 sound level meters?

Frequency range

Acceptance limits for variances in measured decibel levels at specific frequencies in the range of 10 Hz to 20 kHz are one of the most essential specifications of IEC 61672-1:

  • class 1 sound level meters are 16 Hz to 16 kHz,
  • class 2 sound level meters are 20 Hz to 8 kHz.

In practice, this suggests that class 2 sound level meters are not a good option for measuring higher frequencies (for example, cleaning machine parts using compressed air).

Linear operating range

The IEC 61672-1 criterion for the linear operating range is not overly rigorous in terms of decibels, as they demand only 60 dB dynamics between the lowest measured dB and the highest. Professional sound level meters typically offer a much wider operating range, for example, the SV 971A offers 110 dB from 27 dB to 137 dB. The word “linear” is the most important phrase in this context since it indicates that the meter precision in the dB operating range fulfills frequency response requirements.

IEC 61672-1 Temperature operating range

The temperature operating range for a sound level meter that meets IEC 61672-1 should be from -10°C to 50°C for class 1 and 0°C to 40 °C for class 2. In practice, this implies that class 2 sound level meters are not appropriate for measurements in areas where the temperature drops below 0°C (for example, food processing plants).

What is the smallest and largest operation range I'll need?

For environmental noise measurements, you may need a lower range than 30 dB but not necessarily higher than 130 dB. In the case of industrial noise, you will need the upper level to be at least 140 dB Peak (the highest sound pressure level).

Do I need a class 1 or class 2 sound level meter?

Depending on the measurement application, you will use class 1 or class 2. Class 1 is required for environmental noise and building acoustics. For occupational noise, class 2 is usually accepted unless the noise is dominated by high frequencies. If noise measurements are taken in negative temperatures, class 1 is required.

Sound Level Meters Reviews

We’ll go through the finest Svantek sound level meters for classes 1 and 2 below. They’re all digital sound level meters, which means they convert noise levels into decibel readings on a screen in decibel units.

Top-of-the-line sound level meter

The SVAN 979 is the top-of-the-range class 1 sound level meter. It has been on the market for more than ten years, indicating that its software is well established and stable. The meter is packed with a diverse set of features, making it ideal for a wide range of tasks. If you’re looking for a sound level meter to measure noise in extremely quiet places, this is the one to use since it measures down to 12 dBA! It also has an integrated program for conducting building acoustics measurements, including a signal generator that may generate pink noise and white noise. Furthermore, the meter can measure vibration by connecting the vibration sensor instead of the microphone.

The best performance price

If you’re on a budget, the SVAN 977 may be worth considering, which is a comparable model. Some of the features, such as the noise generator, are not included and others are optional, but they all impact on price.

The best class 1 sound level meter

The SV 971A is a third sound level meter in this comparison. This is a new generation sound level meter, which explains why it’s smaller than the 979 and 977. The SV 971A is the best choice for individuals who just want to measure noise without vibrations. Because of the small size, the display type is reflected, but all noise data may be viewed on your smartphone or tablet’s screen thanks to the sound level meter app. The SV 971A is also the most affordable professional sound level meter.

Class 2 sound level meter

The SV 973 is a class 2 sound level meter, which means it’s an ideal tool for measuring noise levels in workplaces. It’s also an excellent sound level meter for classrooms with options for measurement of speech transmissibility and reverberation time. The class 2 designation indicates that the meter is intended to work only in temperature conditions above  0° C and a limited frequency range to 10 kHZ, although it is still a professional type of meter.

Sound level meter calibration

Sound level meters are used to measure sound pressure levels. They are important tools for environmental noise control, product design, and many other applications. To ensure accurate measurements, it is important to calibrate your sound level meter regularly. In this section, we will discuss the process of calibrating a sound level meter and provide some tips on how to do it correctly.

What does the term "calibration" mean?

To verify the sound level meter readings, a sinusoidal sound pressure produced by a sound calibrator is used as a reference source in acoustical calibration. To calibrate the sound level meter, it must be adjusted to the level produced by the sound calibrator.

What is the difference between calibration check and calibration?

When the meter is adjusted to the calibrating signal, we’re talking about calibration. When no changes are required, the calibration check occurs.

When should I calibrate and when should I check?

The calibration should generally be completed before taking a series of measurements. The calibration should be verified (without adjustment) after measurements to compare the readings before and after.

What sound calibrator should I use for my sound level meter?

For class 1 sound level meters the calibrator shall conform to the class 1 specifications of IEC 60942. For class 2 sound level meters, the sound calibrator shall conform to either class 1 or class 2.

Periodic veryfication

Unless it is regulated by local standards, the sound level meter shall be verified in an accredited laboratory in intervals not exceeding 2 years.

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