The SPAD in the chlorophyll meter is an abbreviation for "Development of Soil and Crop Analysis Instruments". SPAD-502 has been promoted to countries all over the world and has been used by the majority of countries to guide the management of nitrogen fertilizers in crops. Its working principle is to emit light through LED light sources of 650 nm and 940 nm. The transmittance of two light sources is detected, the SPAD value is calculated, and the SPAD value is calculated. Inversion of crop chlorophyll content and nitrogen content. Through research, using the 940nm wavelength as a reference, it is affected by the blade thickness. WeChat sweep to get more professional information: Panasonic High-Speed Placement Machine,Samsung Smt Placement Machine,Samsung Smt Placement Machine Brand,Samsung High-Speed Placement Machine KE CHUANG EQUIPMENT(SHENZHEN)CO.,LTD. , https://www.smtkc.com
Chlorophyll meter design to avoid when measuring in the blade. The optical sleeve is tilted due to the thickness of the blade, so that the optical path is inclined. Therefore, a gap of 3 mm in blade thickness is reserved between the optical sleeve and the upper arm of the jig, and at the same time, to ensure that the upper arm of the jig is horizontal in natural conditions, the hinge seat is brought into contact with the upper arm of the jig. Flattened; in the gap between the light sleeve and the upper arm of the fixture is installed a layer of sponge round sheath, can not only play a light-shielding effect on the blade, but also avoid excessive extrusion of the blade to protect the leaf tissue; in order to avoid preventing the secondary Reflected light interference, all mechanical structures of the fixture are blackened; rounding is applied to each edge to prevent damage to the leaf tissue.
The chlorophyll meter is used to measure the SPAD value and the blade thickness to ensure the measurement accuracy and stability. The fixture measurement device is introduced. The device includes an optical measurement system and a corresponding mechanical structure, and the use effect is good. At present, the chlorophyll meter has been put into use, which can analyze the relationship between chlorophyll, leaf thickness and SPAD value of crops at different growth stages such as rice and cotton, and the correlation between SPAD value and chlorophyll content before and after compensation. The next step will be to study the optimal leaf position for crops and establish a chlorophyll regression model for different plant growth stages to provide a theoretical basis and experimental basis for the rational application of nitrogen to increase plant yield. 