Alpha Omega Instruments' series 850 rack-mounted, thermoelectric cooler controllers offer full PID linear temperature control with automatic tuning and provide long-term temperature stability of <0.002 °C. The devices can be configured for TEC power requirements up to 600 W, or 40 A. A choice of temperature sensors can be used for feedback. Options include RS-232 and RS-485 serial communications, as well as a GPIB. The controllers are suitable for electro-optics testing and manufacturing, semiconductor manufacturing and medical diagnostics.