ISOPHOT-S: Capabilities and Calibration (Invited Paper)

The in-flight characteristies of ISOPHOT-S are presented, in particular spectral response function, beam profile, dark current, straylight suppression, and wavelength calibration. Photometric calibration of point-like and extended sources is described. Sensitivity limits and the actual error budget are dis- cussed. The validation of the pipeline products is addressed. Correction methods for signal transients in staring and chopped mode are outiined.