the amplitude of the output signal is ten times higher than that of the input signal. For example, the voltage gain of an amplifier 20 dB can be converted only into a dimensionless ratio - it is equal to 10, i.e. However, it is impossible only in those cases when they talk about relationships. It should also be noted that the conversion of logarithmic units into conventional units is often impossible.
All these units will be discussed later in this article. Note also that a decibel is often used with various suffixes that are often connected to decibel abbreviation dB with a dash, for example, dB-Hz, with a space as in dB SPL, without any intervening character (dBm) or enclosed in parentheses as in dB(m²). Decibels, nepers, etc., which are used with relative logarithmic dimensionless units are simply special names, not their dimensions. It should be noted that all relative logarithmic units are dimensionless. That is, relative logarithmic units are ideal for describing, for example, the gain of an electronic system, that is, the ratio between the output and input signal. Relative logarithmic units, on the other hand, are used to express a physical value as a ratio or proportion of another physical value, for example in electronics where a decibel (dB) is commonly used to express the difference between two signals having arbitrary amplitudes.
For example, 20 dBm = 100 mW or 40 dBV = 100 V. Absolute logarithmic units can be converted into non-logarithmic units of the same physical values. Absolute units are ideal for describing a single value, not a ratio of two values. There are absolute and relative units.Ībsolute logarithmic units express a physical value referenced to some specific value, for example, dBm is an absolute logarithmic unit of power with reference to 1 mW. Logarithmic units are widely used in science, technology and even in everyday things like photography and music. Log 5(25) = 2 Classification of Logarithmic Units In more simple words, a logarithm is an answer to the question: “How many times do we have to multiply one number to get another number?” For example, how many times do we multiply 5 to get 25? The answer is 2 or In other words, the logarithm is a quantity representing the power to which a fixed number called the base must be raised to produce a given number. The logarithm is the inverse operation to exponentiation. Some people even think that logarithmic values more related to the era of slide rules than to the modern digital world. Looks convenient? Yes, but not to everyone! Actually, all people who are not mathematically or technically inclined can be easily confused when dealing with quantities expressed in logarithmic units like decibels. At the same time, the sound power of quiet conversation is 0.000000001 W or 30 dB SWL. For example, the sound power of a Saturn V rocket is 100,000,000 W or 200 dB SWL (dB referenced to the sound power level 10⁻¹² W, it is described below). Logarithmic units allow representing a very large range of ratios by a small convenient number similar to scientific notation. The sound power of a Saturn V rocket is 100,000,000 W or 200 dB SWLĪ logarithmic scale is often used when there is a large range of quantities like sound pressure, earthquake strength, light intensity, various frequency-dependent values like musical intervals, in antenna engineering, electronics, acoustics, RF engineering.
0 kommentar(er)
