[en] Pulse-height analysis is a common technique for broadband X-ray spectrometry. Using a detector with an output which is approximately proportional to the X-ray energy, the pulses are sampled, stored, and digitized. In the analysis of the resulting data, the assumption is normally made that each pulse is due to one and only one X-ray event. Pulse pile-up is the distortion of the measured spectrum which occurs when two or more X-rays arrive within the resolving time of the detector system. As first pointed out by Kane and Hudson this effect will considerably complicate the interpretation of hard X-ray spectra. To achieve the widest range of flare intensities which can be observed, it is necessary to minimize pile-up. (Auth)