These heatable ATR crystals are offered in several materials to accommodate different spectral ranges, sampling conditions, and penetration depth requirements. All are mounted in chemically-resistant holders. They include a K-type thermocouple for monitoring temperature and a 24V heater compatible with our Temperature Controller. The maximum operating temperature is 200ºC for Si, ZnSe and diamond ATR crystals and 80ºC for Ge. The Si and diamond ATR crystals offer highest chemical resistance. The Ge and Si ATR crystals feature a small sampling volume due to their low penetration depth and 250 µm diameter sampling area. The ZnS, ZnSe, and diamond ATR crystals feature a somewhat larger sampling volume with their deeper penetration depth and larger, 500 µm diameter sampling area.