LOGARITHMS AND DECIBELS
A logarithmic scale is often used for vibration velocity and acceleration values due to the very wide range of vibration levels encountered with industrial machinery. Since the measurements of both sound and vibration vary from very low to very high levels, the decibel (dB) is often used. The definition of decibel is
For sound, the standard reference is a pressure of 0.0002 f.Lbar. By definition, doubling the amplitude is equal to an increase of 6 dB.
Two machines each generate 100 dB when operating alone; if they operate in phase, they generate a maximum total noise of 106 dB (not 200 dB).
Related posts:
AUDIO AND VIDEO SYSTEMS - AMPLIFYING SYSTEMS
Inductance:l/r time constants
AUDIO ELECTRONICS:SATELLITE TV
The Bounceless Switch
AIRGAP FIELD SPACE HARMONICS, PARASITIC TORQUES, RADIAL FORCES, AND NOISE
FUNDAMENTALS OF ELECTRIC SYSTEMS:THREE-PHASE SYSTEMS
DC Hipot Test
Representation of Audio Signals:Other Binary Operations
GENERATOR COMPONENTS, AUXILIARIES, AND EXCITATION:COOLING SYSTEMS
The SCR:Phase Shifting the SCR
OBJECTIVE TESTS ON D.C. GENERATORS.
NETWORKING WIRED AND WIRELESS:WIRELESS NETWORKS
Headphones:A Brief History
The Essential Guide to Semiconductors – Theory