level measuring instrument
Levels are the logarithmic measure of two reference quantities relative to each other. They are usually specified in the pseudo unit dB( decibel). With relative levels, the output of an amplifier, for example, is related to the input. In the case of absolute levels, a fixed reference value is used. For example, for the absolute power level in decibels milliwatts( dBm), the reference quantity is 1 mW.
Level meters are used in satellite and antenna technology, in cabling and acoustics, and in news, television and transmission technology. They are used in installation and maintenance work, in the alignment and leveling of antennas, public address systems or radio networks. Depending on whether they measure field strength, voltage level, power level or noise level, they are RF level meters, sound level meters, optical level meters or other level meters.
The functions performed by level meters refer to relative and absolute level measurement, RMS and peak value measurement, instantaneous and time-related measurements and their display in decibels.