Semi anechoic chamber noise and sound pressure level noise are two different indicators for measuring noise levels, and their main difference lies in the measurement environment.

1. Definition and measurement environment

*Semi anechoic chamber noise: refers to the noise value measured in a semi anechoic chamber environment. A semi anechoic chamber is a sealed chamber constructed with certain sound insulation materials and structures, which can reduce the propagation and reflection of noise.
*Sound pressure level noise: refers to the noise value measured in a relatively free spatial environment, usually expressed in decibels (dB).

2. Differences and Applications

*The measurement results of semi anechoic chamber noise mainly reflect the propagation and reflection of noise in a closed environment, which is closer to the actual noise situation of equipment (such as range hoods) during use.
*Sound pressure level noise reflects the propagation of noise in a free environment.
*In practical applications, semi anechoic chamber noise more accurately reflects the noise situation of the equipment and can eliminate interference from other natural sounds, making it more in line with relevant national standards and requirements.

3. Selection and application suggestions

*When choosing a device (such as a range hood), consumers can understand the semi anechoic chamber noise and sound pressure level noise of the product by viewing its technical parameters.
*Generally speaking, products with lower noise levels in semi anechoic chambers have lower noise levels and are a better choice.
*At the same time, it is also necessary to consider comprehensively based on one's own usage environment and needs, and choose products that are suitable for oneself.

In summary, both semi anechoic chamber noise and sound pressure level noise are indicators for measuring noise levels, but the different measurement environments make the two different in their applications. When choosing equipment, one should fully consider these two noise indicators as well as their actual needs and usage environment.