Now I regonized several entries to be empty, i.e. there are no values in the xml but still the names
(see http://meteo.selfip.info/download/all-sensors_user.xml)
- wind_maindir
- cloudheight_trend
- maindir_trend
- radiation_trend
- uv_index_trend
- last15m_localdate2
- last15m_thb0_fc
- last15m_th0_hum_abs
- last15m_wnid1_dir_de
- last15m_th0_cloudheight_m
- last15m_sol1_radiation_rel
- last15m_uv1_index
- last15m_..._trend
- ...
- last60m...
- last60m_..._trend
- last60m_wnid1_dir_de
- last24h...
- last24h_..._trend
- ...
