IRE (unit)

Signal curve of the composite video signal. There is a 140 IRE between the lowest and highest signal level.

The IRE unit is a unit of measurement that is used to assess the level of analog television signals (abbreviated FBAS, composite video ). It is particularly widespread in North America and is derived from the abbreviation of the former organization Institute of Radio Engineers (IRE).

A value of 100 IRE is defined as the signal deviation between black and white video image content. Here, 0 IRE the black image content and a corresponding voltage of 0 V. The composite synchronizing pulses in the blanking interval normally lie below this black level and are set at a level of -40 IRE. This means that a composite signal comprises a minimum to a maximum signal level of 140 IRE.

The unit IRE is a relative, dimensionless unit and can be compared with a level specification and is used in the ITU-R BT.470 standard to describe the NTSC , PAL and SECAM video standards.

Individual evidence

1. ↑ Robin & Poulin, Michael Robin, Michel Poulin: Digital television fundamentals: design and installation of video and audio systems . McGraw-Hill Professional, 2000, ISBN 0071355812 , p. 17.