Knowledge Bank

It is proposed that the Zeeman effect of the $202\to 111$ transition in sulfur dioxide be used as a magnetic field calibration standard. The recent accurate beam maser measurements on this transition by Ellenbroek and $Dymanus1$ have been confirmed by electric resonance measurements in the $111$ level. The Zeeman splittings most useful for calibration purposes depend linearly on the magnetic field. For perpendicular selection rules the Zeeman coefficient is 0.5282(3) MHz/kg, and 0.3722(3) MHz/kg applies to parallel selection rules.