SHEL LAB Diurnal growth chambers are designed for studies requiring day and nighttime simulation. This unit features dual-program selector dials, which allows control of two temperature conditions and an ON/OFF illumination cycle relative to the program selected. Each system operates independently allowing for simulation of a diurnal cycle, such as an eight hour day cycle of 30°C with light followed by a sixteen hour night cycle of 18°C without light. Forced air circulation ensures the most reproducible test conditions. The chamber air is gently and continuously circulated at a rate that ensures temperature uniformity of all test samples. The unit is equipped with a hermetically-sealed compressor and an independent over temperature safety controller. In addition, a one amp interior outlet allows use of shakers, stirrers, roller bottles or other apparatus. This chamber is ideal for plant growth studies.