# Appendix B. Units

The International System of units (SI) is founded on base 10 calculations. Not because we hate imperials; just because we have 10 fingers.

Here is a short list of the names covering the powers of ten used in this book.

Name |
Abbreviation |
Scientific format |
Decimal value |
Example |

micro |
µ | 10^{-6} |
0,000001 | 1 µPa = 0,000001 Pa |

milli |
m | 10^{-3} |
0,001 | 1 mV = 0,001 V |

deci |
d | 10^{-1} |
0,1 | 1dB = 0,1 B |

kilo |
k | 10^{3} |
1000 | 1 kHz = 1000 Hz |

Here are the basic units used in this book.

Name |
Abbr. |
SI equivalent |
Measured value |
Example |

Ampère |
A | A | Electric current | US toaster: 12,5 A |

Bel |
B | — | Sound intensity ratio | Human hearing threshold: 0 dB |

Celsius |
°C | °C | Temperature | Absolute zero: -273,15 °C |

Fahrenheit |
°F | 1.8 °C + 32 | Temperature | Normal body temperature: 98.6 °F |

Foot |
ft. | 0.3048 m | Length, distance | Height of basketball rim: 10 ft. |

Hertz |
Hz | 1 / s | Frequency | Middle C on a piano: 261.6 Hz |

Inch |
In. | 0.0254 m | Length, distance | One foot is 12 inches |

Ohm |
Ω | kg m^{2} / s^{3 }/ A^{2} |
Resistance, impedance | Copper wire 5 m long 2 mm^{2} section: 0,04 Ω |

Meter |
m | m | Length, distance | Long jump world record: 8.95 m |

Pascal |
Pa | kg / m / s^{2} |
Pressure | Atmospheric pressure: 1.01 kPa |

Volt |
V | kg m^{2} / s^{3} / A |
Electric potential | Nerve cell resting potential: 75 mV |

*Table **13** Units Used in Audio Basics*

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