Transmitter power readings are most commonly referenced to which power level?

The most common reference power level for transmitter power readings is indeed 1 milliwatt. This standard is widely used because it provides a convenient baseline for calculating power levels in decibels (dBm). The decibel scale is logarithmic, and referencing power to 1 milliwatt allows for easy comparison and conversion between different power levels. When measured in dBm, 0 dBm corresponds to 1 milliwatt, and other power levels can be expressed as positive or negative values relative to this reference.

Using 1 milliwatt as a reference simplifies the process of understanding signal strength and allows technicians to quickly assess the performance of a transmitter without converting from other units. This is especially important in radio communications, where power levels can vary significantly, and clarity in measurement ensures optimal performance and compliance with regulations.