Diagnostics at the MAX IV 3 GeV storage ring during commissioning

The MAX IV 3 GeV storage ring based on a multibend achromat lattice allows for horizontal emittances from 330 pm rad down to 180 pm rad, depending on the number of insertion devices. The diagnostics used during commissioning will be described, with emphasis on the emittance diagnostics. This will involve two diagnostic beam lines to image the electron beam with infrared and ultraviolet synchrotron radiation from bending magnets, in order to determine also beam energy spread. The scheme for horizontal emittance measurements looks promising also for an order of magnitude lower emittance. Bunch lengthening with harmonic cavities is essential for the low emittance machine performance. We have used a radiation-based sampling technique to verify individual bunch distributions.