Что делает the взвешенный взвешивание of a шум метр среднее?
Сигнал Шум Соотношение, также Известный Как Сигнал К Шум Соотношение,
It refers to the ratio of useful signal power to useless noise power. Обычно, as power is a function of current and voltage, the signal-to-noise ratio can also be calculated using voltage, which is the ratio of signal level to noise level. Однако, the calculation formula is slightly different. Вычислить сигнал/шум отношение основано на мощность соотношение: S/N=10 log Вычислить сигнал/шум отношение based on voltage: S/N=10} log Due to the logarithmic relationship between signal-to-noise ratio and power or voltage, it is необходимо к значительно увеличение the ratio of output value to noise value. For example, when the signal-to-noise ratio is 100dB, the output voltage is 10000 times the noise voltage. Для электроника схем, это есть не an easy задача. Влажность датчик зонд, нержавеющая сталь сталь электрик нагрев трубка PT100 датчик, литей алюминий нагреватель, нагрев змеевик жидкость соленоид клапан
If an amplifier has a high signal-to-noise ratio, it means that the background is quiet. Due to the low noise level, many weak sound details masked by noise will appear, resulting in increased floating sound, enhanced air sense, and increased dynamic range. There is no strict discrimination data for measuring whether the signal-to-noise ratio of an amplifier is good or bad. Generally speaking, it is better to be around 85dB or above. Below this value, it is possible to hear obvious noise in music gaps during certain loud listening situations. In addition to signal-to-noise ratio, the concept of noise level can also be used to measure the noise level of amplifiers. This is actually a signal-to-noise ratio value calculated using voltage, but the denominator is a fixed number: 0.775V, and the numerator is the noise voltage. Therefore, the difference between noise level and signal-to-noise ratio is: the former is an absolute number, while the latter is a relative number.
After the specification sheet data in many product manuals, there is often an A word, meaning A-weight, which refers to modifiing a certain value according to certain rules. Поскольку человек ухо есть особенно чувствительный к промежуточный частота, if the signal-to-noise ratio in the intermediate frequency band of an amplifier is large enough, even if the signal-to-noise ratio is slightly lower in the low-frequency and high-frequency bands, it is not easy for the human ear to detect. It can be seeen that if the weighting method is used to measure the signal-to-noise ratio, its value will definitely be выше чем если the weighting method is not used. In terms of A weighting, its value will be higher than without weighting.
In addition, in order to simulate the different sensitivities of human auditory perception at different frequency, there is a network in the sound level meter that can simulate the auditory характеристики of the human ear and correct the electrical signal to approx the auditory sensation. This network is called a weighted network. The Звук Давление Уровень Измеренный Через А Взвешенный Сеть Есть Нет Дольше Ан Объектив Физический Количество (Называемый Линейный Звук Давление Уровень Уровень), Но А Звук Давление Уровень Скорректирован По Слуховой Восприятие, Вызванный Взвешенный Звук Уровень или Шум Уровень.
Там есть общие три типы из взвешенные сети: A, B, и C. A-взвешенный звук уровень имитирует частота характеристики из низкий интенсивность шум ниже 55дБ в в человек ухо, B-взвешенный звук уровень имитирует частота характеристики из средняя интенсивность шум от 55дБ до 85дБ, и C-взвешенный звук уровень имитация частота характеристики из высокий интенсивность шум. The main difference среди the three is the degree of of затухание of the low-frequency components of the noise, with A haveing the most затухание, B взятие second place, and C имеющий the least. A-взвешенный звук уровень является текущим the most wide used type of noise measurement in the world due to its characteristic curve close to the auditory характеристики of the human ear, while B and C are постепенно not используется.
The noise level reading obtained from the sound level meter must indicate the measurement conditions. If the unit is dB and an A-weighted network is used, it should be recorded as dB (A).
