Modern infrared spectrometers contain many detectors. The Atmospheric Infrared Sounder (AIRS) has 4482 infrared detectors. The Cross-track Infrared Sounder (CrIS) (a Fourier Transform Spectrometer) has 27. This paper examines issues related to multiple detectors and describes their impact on calibration and data analysis, using examples from AIRS and CrIS. The potential differences among detectors are not limited to dead channels. They can include: noise characteristics, spatial response, illumination through the optical system, and exposure to radiation. The more detectors in an instrument, the more important it is for both the hardware and data analysis software designers to be prepared to handle such differences. Techniques used to mitigate these effects are described in this paper.