In order to calibrate bolometer observations one needs to compare them to the measurement of a source with a well known flux. The best calibrators are Mars and Uranus but since they are not always visible, it is desirable to have a group of ``secondary'' calibrators, i.e. objects which are calibrated with respect to the planets, and that can be observed at any LST.
For this purpose we have observed in spring 1999 and spring 2000 a group of secondary calibrators. The measurements included mapping of the objects in order to determine their shape and extent and On/Off measurements yielding their flux density per beam.
The summary of these observations, including tables of flux densities per beam for the secondary calibrators, is now available for observers under the following URL: (http://www.iram.es/Telescope/manuals/Report/second_calib.ps)