An Installation and Method for Measuring Photosynthetic Rate of Plant Population

In this paper, the principle of design and constitution of the installation for measuring photosynthetic rate of plant population, and methods of measurement and calculation were introduced. This installation with semi-closed measurement system and CO₂ infrared gas analyser, can measure and control change of CO₂ concentration continuously in an assimilation chamber. Its measurement range is: 0～1000 ppm; resolution; 2 ppm. Good results by using this installation to measure photosynthetic rates of wheat, corn, soybean and Chinese cabbage under different concen-trition of CO₂ had been achieved.