Leveraging from a survey of UK users, manufacturers and developers, the authors identify the factors influencing the accuracy of measurements obtained with detector array equipment, develop calibration techniques, and establish best practice procedures. The text contains both a review of the existing literature and a large amount of new experimental data obtained during the course of the study. The main emphasis is on UV, visible, and near-infrared systems that use silicon detector technology. The authors also address the issues arising in thermal imaging with infrared detector arrays and include brief sections on EM CCDs for low-light-level imaging and on lag effects in CMOS active pixel sensors.