IRE

dimensionless unit used to measure the amplitude of a composite analog video signal, named for the Institute of Radio Engineers. On a waveform monitor, the scale typically runs from -40 to 100 IRE, where 100 IRE represents peak white and 7.5 IRE (for NTSC with setup) or 0 IRE represents reference black. It serves as the standardized unit for ensuring luma levels are within legal broadcast limits.