Measurement and Control of Greenhouses by Carbon Dioxide Detector
The greenhouse is a relatively closed environment, which makes the concentration of carbon dioxide and day and night changes greatly, which affects the growth of plants. The use of modern electronic carbon dioxide detectors can measure and control the concentration of carbon dioxide according to the growth needs of various plants. The concentration of carbon dioxide is controlled in the best situation in the greenhouse to maintain the best growth environment and make the plants get the best. reward.
The concentration of carbon dioxide in the greenhouse was the highest in the morning, reaching 1.2mL/L, measured by a carbon dioxide detector; with the enhancement of plant photosynthesis during the day, the concentration of carbon dioxide remained at a relatively low level. After 16 o'clock in the afternoon, the photosynthesis of plants weakens, and the concentration of carbon dioxide begins to rise; at night, under the action of plants and soil, carbon dioxide is released, making the concentration of carbon dioxide gradually reach the highest point in the day. In the greenhouses of other crops, the carbon dioxide concentration also had similar changes.
In order to improve the measurement accuracy, it is necessary to control the temperature of the solution in the reactor. The thermistor was used as the temperature sensor, and the resistance wire was used as the heater to keep the temperature of the solution at 25°C. While measuring the concentration with a high-precision carbon dioxide detection instrument, record the output voltage value of the phototransistor, store the concentration of carbon dioxide and the corresponding voltage value in the single-chip microcomputer in the form of a table, and use it for the single-chip microcomputer control program.
The automatic control of the greenhouse carbon dioxide detector is different from the general automatic single-loop PID control. It is a measurement and control system based on logical judgment based on intelligent control. The purpose of studying the influence of carbon dioxide concentration is to develop a low-cost equipment suitable for the modernization of rural agriculture in China. The success of the control system through the CO2 detector depends to a large extent on the accuracy and completeness of the database related to crop growth and CO2 concentration.
