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Home > The most cost-effective helmet within 500

The most cost-effective helmet within 500

Shanghai Sunland Industrial Co., Ltd is the top manufacturer of Personal Protect Equipment in China, with 20 years’experience. We are the Chinese government appointed manufacturer for government power,personal protection equipment , medical instruments,construction industry, etc. All the products get the CE, ANSI and related Industry Certificates. All our safety helmets use the top-quality raw material without any recycling material.

Why choose us

Solutions to meet different needs

Solutions to meet different needs

We provide exclusive customization of the products logo, using advanced printing technology and technology, not suitable for fading, solid and firm, scratch-proof and anti-smashing, and suitable for various scenes such as construction, mining, warehouse, inspection, etc. Our goal is to satisfy your needs. Demand, do your best.

Highly specialized team and products

Highly specialized team and products

Professional team work and production line which can make nice quality in short time.

We trade with an open mind

We trade with an open mind

We abide by the privacy policy and human rights, follow the business order, do our utmost to provide you with a fair and secure trading environment, and look forward to your customers coming to cooperate with us, openly mind and trade with customers, promote common development, and work together for a win-win situation.

24 / 7 guaranteed service

24 / 7 guaranteed service

The professional team provides 24 * 7 after-sales service for you, which can help you solve any problems

Certificate of honor


CONTACT USCustomer satisfaction is our first goal!

Consultation hotline:0086-15900663312

Address:No. 3888, Hutai Road, Baoshan District, Shanghai, China

The most cost-effective helmet within 500

Empirical calculation of sound insulation in lightweight ...

Empirical calculation of sound insulation in lightweight ...

dicted ,values, to the measured results. Our prediction is based on equations in the European Standard EN 12354-1 and well-known empirical models, with empirical corrections from the measurements. Articles have also provided us with both guidance on how to calculate the ,sound insulation, and simplified methods for handling uncertainties and safety

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What do Rw Ctr and NRC mean? | BUILD

What do Rw Ctr and NRC mean? | BUILD

The higher the Rw/Rw+Ctr ,values, of a ,sound insulation, product, the better the product will perform as soundproofing. NRC ,values, on room finishes will contribute to the ,sound, landscape too; higher ,values, will ‘deaden’ the ,sound, in a room, lessening the reverberation of …

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What Is the Noise Reduction Rating (NRR) and How to Use It?

What Is the Noise Reduction Rating (NRR) and How to Use It?

The NRR is then calculated from the means (using two standard deviations) in this attenuation table, assuming pink noise with a ,sound, level of 100 dB at each frequency. Note that while the ,earmuffs, and earplugs in the example above have almost the same noise reduction rating, there is a marked difference between the two at different frequencies.

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What Is Noise Reduction Coefficient (NRC) And Sound ...

What Is Noise Reduction Coefficient (NRC) And Sound ...

17/2/2020, · It is derived from the ,sound, attenuation ,values, tested on the frequency range of 125 Hz to 4000 Hz and it measured the deduction rate of the sounds in the dB scale. If a ,sound, coming from the other side of the wall is a 30 dB but after passing through isolation or wall it reduces to 10 dB that means the STC rating of the wall is 20.

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What Is the Noise Reduction Rating (NRR) and How to Use It?

What Is the Noise Reduction Rating (NRR) and How to Use It?

The NRR is then calculated from the means (using two standard deviations) in this attenuation table, assuming pink noise with a ,sound, level of 100 dB at each frequency. Note that while the ,earmuffs, and earplugs in the example above have almost the same noise reduction rating, there is a marked difference between the two at different frequencies.

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The correct way to buy anti-noise earplugs - Eastragon ...

The correct way to buy anti-noise earplugs - Eastragon ...

There are several types of ,sound insulation, earplugs such as memory foam earplugs, silicone earplugs, silicone earplugs, wax pill earplugs, etc. The quality of ,sound insulation, earplugs mainly depends on the noise reduction ,value,, softness, durability, safety indicators, appearance and shape of the earplugs, below Let’s learn more about it together.

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Is the soundproof earplug useful?-SUNLAND

Is the soundproof earplug useful?-SUNLAND

Good products have an ,average sound insulation value, between 36-40 decibels in various frequencies, and some products have a maximum ,sound insulation value, of 50 decibels, which can isolate 80 to 90% of ambient noise.

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Typical U Values for Walls | Insulation Specialists | Home ...

Typical U Values for Walls | Insulation Specialists | Home ...

As you can see, on their own without added ,insulation,, cavity walls have a better U ,value, than solid walls. Typical U ,Values, for Walls. Below are the typical U ,values, you’d expect to measure within a solid wall, an uninsulated cavity wall, and an externally insulated wall of any …

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Typical U Values for Walls | Insulation Specialists | Home ...

Typical U Values for Walls | Insulation Specialists | Home ...

As you can see, on their own without added ,insulation,, cavity walls have a better U ,value, than solid walls. Typical U ,Values, for Walls. Below are the typical U ,values, you’d expect to measure within a solid wall, an uninsulated cavity wall, and an externally insulated wall of any …

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CASE STUDY: ACOUSTICS OF AN INDOOR SHOOTING RANGE

CASE STUDY: ACOUSTICS OF AN INDOOR SHOOTING RANGE

The ,value, calculated for the ,sound insulation, single ,value,, equivalent to D nT w,, is ... ,Average sound, pressure levels in the source room with the OmniPower ,sound, source and ... =107.2 dB (A). For an 8-hour working day, the ,sound, levels without ,ear muffs, correspond to L Ex h,8 =107.2 dB(A) and a ,value, …

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Is the soundproof earplug useful?-SUNLAND

Is the soundproof earplug useful?-SUNLAND

Good products have an ,average sound insulation value, between 36-40 decibels in various frequencies, and some products have a maximum ,sound insulation value, of 50 decibels, which can isolate 80 to 90% of ambient noise.

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Audiometer

Audiometer

Average Sound insulation value of earmuff, Environmental Noise Monitor Possible for Measurement (Green light is lit.): 1000 Hz: 30 dB or less, 4000 Hz: 30 dB or less Caution needed for measurement (Yellow light is lit.): 1000 Hz: 30 to 37 dB or less, 4000 Hz: 40 to 50 dB or less

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What do Rw Ctr and NRC mean? | BUILD

What do Rw Ctr and NRC mean? | BUILD

The higher the Rw/Rw+Ctr ,values, of a ,sound insulation, product, the better the product will perform as soundproofing. NRC ,values, on room finishes will contribute to the ,sound, landscape too; higher ,values, will ‘deaden’ the ,sound, in a room, lessening the reverberation of …

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Safety Muffs Noise Reduction Folding Headband Earmuffs ...

Safety Muffs Noise Reduction Folding Headband Earmuffs ...

Find many great new & used options and get the best deals for Safety Muffs Noise Reduction Folding Headband ,Earmuffs, Hearing ,Sound Insulation, at the best online prices at eBay! Skip to main ... 5.0 ,average, based on 1 product rating. 5. 1 users rated ... Good ,value, for money. Acceptable performance around aircraft, chainsaws nail gun and the ...

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Best Shooting Ear Protection – | Top 10 REVIEWS – Nov 2020

Best Shooting Ear Protection – | Top 10 REVIEWS – Nov 2020

NRR ,Value, of 30 dB: When external ambient ,sound, reaches 82 dB, this device will shut off amplification automatically. However, the R-01902 model has 30 dB Noise Reduction Rating ,value, that supports natural listening and communication.

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The 5 Best Noise Reduction Earmuffs Review - NoisyWorld

The 5 Best Noise Reduction Earmuffs Review - NoisyWorld

After prolonged use, the ear cushions of any ,earmuffs, will wear out and the ,insulation, foam inside the cups can get dirty or deteriorate. Both the ear cushions and the ,insulation, foam are user-replaceable and readily available for purchase in a hygiene kit.

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Is the soundproof earplug useful?-SUNLAND

Is the soundproof earplug useful?-SUNLAND

Good products have an ,average sound insulation value, between 36-40 decibels in various frequencies, and some products have a maximum ,sound insulation value, of 50 decibels, which can isolate 80 to 90% of ambient noise.

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Recommended Home Insulation R–Values - Energy Star

Recommended Home Insulation R–Values - Energy Star

Recommended Home ,Insulation, R–,Values,. ,Insulation, level are specified by R-,Value,. R-,Value, is a measure of ,insulation,’s ability to resist heat traveling through it. The higher the R-,Value, the better the thermal performance of the ,insulation,. The table below shows what levels of ,insulation, are cost-effective for different climates and ...

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The 5 Best Noise Reduction Earmuffs Review - NoisyWorld

The 5 Best Noise Reduction Earmuffs Review - NoisyWorld

After prolonged use, the ear cushions of any ,earmuffs, will wear out and the ,insulation, foam inside the cups can get dirty or deteriorate. Both the ear cushions and the ,insulation, foam are user-replaceable and readily available for purchase in a hygiene kit.

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Best Earmuffs For Sleeping In 2020 - TOP 10 Best Reviewed

Best Earmuffs For Sleeping In 2020 - TOP 10 Best Reviewed

It has powerful ,sound insulation, and noise-canceling capabilities. It offers up to 27 NRRs. Such headphones can easily have 34dB ,of earmuffs,, but they are not because the headband was designed to put less effect on your ears for lasting comfort.

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