Overview
Engineering reference data for Signal Transmission Sensor Controller in acoustics.
Key Formulas
Speed of Sound
Speed of sound in an ideal gas.
Sound Level
Decibel level.
Wavelength
Wavelength = speed / frequency.
Variables
| Symbol | Description | Unit |
|---|---|---|
| Speed of sound | m/s | |
| Sound level | dB | |
| Wavelength | m | |
| Frequency | Hz |
Signal Transmission Standards
Industrial process control relies on standardized signals to ensure compatibility between sensors and controllers. The most common standards are:
The 4-20 mA current loop is particularly prevalent in industrial environments due to its immunity to voltage drop over long cable runs and ability to power two-wire transmitters (4 mA often represents the zero value or powers the device).
Modern Digital Protocols
Beyond analog standards, modern industrial communication increasingly uses digital "smart" protocols over wired or wireless networks. These systems offer bidirectional communication, allowing for diagnostics, configuration, and more complex data from field devices. Examples include HART (superimposed on 4-20 mA), Profibus, Foundation Fieldbus, and various industrial Ethernet variants.