What is a sound level meter and how does it work?
A sound level meter measures:
- Time-averaged and exponentially time-weighted sound levels
- Frequency-weighted noise levels
- Frequency-weighted average noise exposure levels.
Sonometers and noise meters are all synonyms for sound level meters. IEC 61672 defines noise level meters as a microphone, preamplifier and signal processor. A display displays the noise results. The hand-held noise level meters can be powered by batteries and have a triangular tip with windscreen.
What are the various types of sound level meters available?
- Class 1 Noise Level Meters: The most accurate and expensive noise level meter. They meet IEC 61672-1 standards and have a type approval
- Class2 Sound Level Meter: A less accurate and more expensive noise level meter that complies with IEC 61672-1 standards
- Low-cost sound meters that do not comply with IEC 61672, are usually sold in markets
Which sound level meter is best for me?
Finding the right sound meter can be difficult. The first step is to decide how you will use the sound level meter in australia. Professional sound pressure measurements usually follow standard procedures that specify the type of soundmeter. A mobile app is as effective as a market sound level meter if you are looking to measure noise.
Applications for noise measurement
These are the most popular types of professional sound-measuring applications:
- Occupational noise
- environmental noise
- Acoustics in building and rooms
- Various engineering sound measurements.
Different types of pro sound meters
There are two types of pro-sound meters.
- Sound level meters of class 1
These meters are the most expensive and accurate. These meters are used for professional measurements like environmental noise (traffic, railway, and aircraft noise), building noise, engineering measurements, and sound power.
- Class 2 sound level meters
These meters are cheaper and provide more accurate measurements. These are used in offices, classrooms, and general industrial settings.
Types of noise level meters to measure occupational noise
Class 2 sound level meters are generally acceptable for workplace noise surveys, unless otherwise stated in the measurement standard.
How can I find the best sound level meter to suit my needs?
When choosing a noise level meter, there are several things to take into consideration:
- What kind of noise environment are you measuring?
A Class 1 sound level meter is required to measure environmental noise. A Class 2 sound level meter is best for industrial sound measurements.
- What sound pressure levels are you able to measure?
The noise level range for most sound level meters is between 30-130 dB. The object being measured will determine the range you require. You may need a range lower than 25 dB for environmental noise measurements but not necessarily as high as 140 dB. For industrial noise, the upper limit must be at least 140dB.
- How much do you have to spend on a sound level meter.
Although Class 1 meters cost more than Class 2, both can provide accurate sound measurements provided they meet the IEC 61672-1 standards.
IEC 61672 Sound Level Meters
International standard IEC 61672-1 specifies performance criteria for professional sound pressure meters. This standard specifies two performance categories: class 1 or class 2.
These are the essential components of sound level meters that conform to this standard.
- linear operating range
- Frequency response
- Temperature operating range
What is the difference between IEC61672 Class 1 & Class 2 sound level meters
In general, Class 1 sound level meters are better and more expensive that Class 2.
Frequency range
IEC 61672-1’s most important specifications include acceptance limits for deviations in measured decibel levels at frequencies within the range of 10Hz to 20kHz.
- Class 1 sound level meters range from 16 Hz to 16 KHz.
- Class 2 sound level meters range from 20 Hz to eight kHz.
This means that class 2 sound levels meters won’t be able to measure higher frequencies in practice (e.g. cleaning parts of machines using compressed air).
Linear operating range
IEC 61672-1 does not require a high level of decibels for linear operation. They only need 60 dB dynamics to distinguish between the lowest and highest measured dB. Professional noise level meters usually offer a wider operating range. The SV 971A, for instance, offers 110 dB between 27 dB and 137 dB. In this context, the word “linear” represents that precise measurements within the dB operating range meet frequency response requirements.
IEC 61672-1 Temperature operating temperature
A sound level meter meeting IEC 61672-1’s temperature operating range should be between -10degC and 50degC in class 1 and 40degC in class 2. This means that sound level meters of class 2 are not suitable for precise measurements in areas below 0degC (e.g. food processing plants).
What is the smallest or largest range of operation I will need?
You may require a lower range than 30dB for environmental noise measurements but not necessarily a higher one than 130dB. For industrial sound, the maximum level required is at least 140dB Peak (the highest level of sound pressure).
Do I need a sound level meter of class 1 or 2?
You will choose between class 1 and class 2 depending on your measurement application. For environmental noise, building and room acoustics, class 1 is required. Class 2 is acceptable for occupational noise, unless it is dominated or dominated by high frequencies. Class 1 is required for sound level measurements in cold temperatures.
Sound Level Meters Reviews
Below, we’ll be reviewing the best Svantek professional noise level meters for classes 1 & 2. All of them are digital noise level meters. This means that they convert noise levels into decibel readings.
High-quality sound level meter
The SVAN 979 class 1 integrating sound level meter is the best-of-the range model. The meter has been in use for over ten years. This indicates that the software is stable and well-established. It is equipped with many features that make it suitable for a variety of tasks. This is the best sound level meter for measuring noise in very quiet areas. It measures down to 12 decibels! The integrated program allows you to conduct sound insulation measurements. It even has a signal generator which may produce pink noise or white noise. The vibration sensor can be connected to the meter instead of the microphone.
Best performance at a great price
The SVAN 977, which is a similar model, may be worth looking at if you have a tight budget. Although some features aren’t included or are optional, they all have an impact on the price.
The highest class 1 sound level meter
This is the third sound level meter, the SV 971A. This new generation sound level meter is smaller than the 979 or 977. Individuals who only want to measure noise and vibrations will find the SV 971A the best option. The instrument’s small size means that the display is not large enough to be easily viewed, but you can view all noise data on your phone or tablet using the sound level meter app. The SV 971A professional noise level meter is also one of the most affordable.
Sound level meter class 2
The SV 973 class 2 sound level meter is ideal for measuring noise levels at work. The SV 973 is a great meter to measure sound levels in classrooms, with the ability to measure speech transmissibility or reverberation. It is still a professional type meter, but the class 2 designation means that it can only measure sound waves in temperatures above 0°C and within a narrow frequency range of 10 kHz.
What is frequency weighting?
IEC 61672 defines frequency weighting as the difference between the frequency-weighted signal on the meter and the level of a constant amplitude sinusoidal input.
The most common sound level meters use the A, C, or Z frequency weightings. A-weighting is the most common, and it is used to measure L Aeq. C-filter uses lower frequencies to attenuate than A-weighting. C-weighting can be used to measure low frequencies by comparing L Ceq with L Aeq levels. C-weighting can also be used to measure peak sound levels. Z-weighting is a frequency spectrum instrument that has a flat frequency response between 10 Hz and 20 Hz. It is commonly used to measure frequency spectrum in octave band.
What’s the difference between a noise level meter or a noise dosimeter, and how can you tell?
A noise dosimeter, a small sound level meter attached to the clothing of a person, is used to measure noise exposure during workdays and noise dose. IEC 61252 noise meters meet the requirements for class 2 sound level meters.
What is the difference in sound exposure and noise exposure levels?
Noise dosimeters calculate the noise exposure level LEX using L AEQ that is then normalized to 8 hours. The sound exposure level is the time-averaged L AEQ over an average time interval that has been normalized to 1.
Sound level meter calibration
The purpose of sound level meters is to measure sound pressure levels. These meters are essential tools in environmental noise control and product design. It is essential to calibrate your sound level meter on a regular basis in order to ensure accurate measurements. We will be discussing the calibration process and providing tips for doing it correctly in this section.
What does “calibration” actually mean?
A reference source for acoustical calibration is a sinusoidal pressure level that has been produced by a sound calibrator. This level can be used to verify the sound level meter readings. The sound level meter must be calibrated to the sound calibrator’s level.
What is the difference between calibration and calibration check?
When the meter is calibrated to the calibration signal, we refer to calibration with adjustment. The calibration check is performed if there are no adjustments.
When and how should I calibrate?
Before taking any series of measurements, the calibration should be done. After taking measurements, the calibration should be confirmed (without adjustments) to allow for comparison of readings.
Which sound calibrator should be used for my sound level meter
The class 1 specifications of IEC60942 shall be used for calibrators. The sound calibrator for class 2 noise level meters must conform to either IEC 60942 class 1 or 2.
Periodic verification
The sound level meter must be checked in an accredited laboratory at intervals of not more than 2 years, unless it is required by local standards.
