### Determination of the Integrated Luminosity at HERA using Elastic QED Compton Events.

Stefan Schmitt
A measurement of the integrated luminosity at the $ep$ collider HERA is presented, exploiting the elastic QED Compton process $ep\to e\gamma p$. The electron and the photon are detected in the backward calorimeter of the H1 experiment. The integrated luminosity of the data recorded in 2003 to 2007 is determined with a precision of \totalerr{}. The measurement is found to be compatible with the corresponding result obtained using the Bethe-Heitler process.