FAPOL was commissioned on the 15th and 16th of February. Both linear and circular photometry and spectroscopy was tested. Also, the software by Roy Ostensen for the `fast-photometry' mode was tested. All tests went well, except for a problem with the interlock to the calibration unit, which was fixed shortly after. Because of this, no calibrations using lamps were made. Quick and preliminary reductions of standards verified that we obtain the expected amount of circular polarization in the spectra. In Table 5 the transmission of the half-wave plate plus calcite per filter is given. Here, the efficiency is defined by the flux measured for a star in the ordinary plus extra-ordinary beam, divided by the flux measured when the star is observed with the filter alone.
The retarder plates should be only changed by staff, therefore we do not recommend that linear and circular mode can be interchanged during a run. The default setup in FAPOL will be the half-wave plate. Per default, at least the calcite plate for imaging will be installed in case of GRB imaging polarimetry requests.