We developed the testo 871s thermal imager together with our experienced professionals to enable you to work quickly and easily with professional thermal imaging technology. You can generate error-free and objectively comparable infrared images using its handy functions. The IFOV warner, testo ɛ-Assist and testo ScaleAssist mean you can avoid measurement errors and not only effortlessly achieve optimum setting of emissivity (ɛ) and reflected temperature (RTC) for building thermography, but also of colour scale.