## Going from to

In CLASS, the brightness scale is assumed to be expressed in when the forward and beam efficiencies are equal. To check this, you can type

    LAS> EXAMINE R%HEAD%CAL%BEEFF R%HEAD%CAL%FOEFF
    R%HEAD%CAL%BEEFF = 0.9600000    ! Real    GLOBAL RO
    R%HEAD%CAL%FOEFF = 0.9600000    ! Real    GLOBAL RO

In this case, if the source properties are better represented by the main temperature scale ( ), you can convert the scale from to with

    LAS> EXAMINE R%HEAD%HER%ETAL R%HEAD%CAL%FOEFF  ! Check that they have identical values
    R%HEAD%HER%ETAL = 0.9600000     ! Real    GLOBAL RO
    R%HEAD%CAL%FOEFF = 0.9600000    ! Real    GLOBAL RO
    LAS> EXAMINE R%HEAD%HER%ETAMB                  ! Check that the beam efficiency is sensible
    R%HEAD%HER%ETAMB =   0.6223738  ! Real    GLOBAL RO
    LAS> MODIFY BEAM_EFF R%HEAD%HER%ETAMB          ! Scale conversion
    I-MODIFY,  Former beam efficiency: 0.9600, new: 0.6224

The MODIFY BEAM_EFF command will multiply the spectrum by R%HEAD%CAL%FOEFF / R%HEAD%HER%ETAMB and change the associated header parameters accordingly, e.g. baseline rms and .