# Units od Intensity (AU)

1. Jun 28, 2010

### russel.arnold

I know that the SI unit of Intensity is W/m^2. I came across one more unit of intensity -> AU..but could not get much on that. Can anybody tell me the conversion formula ( from SI to AU ) ?

2. Jun 29, 2010

### Zarqon

When displaying intensity AU or Arb.u., mostly certainly measn 'Arbitrary units', which means that the absolute value of the intensity is not known and/or not important. For intensities, quite often it's enough to know only the relative value, e.g. when inferring a decay time constant from an intensity curve.