Chlorophyll Meter Portable Plant Nutrition Tester/Analyzer
Working principle
The working principle of chlorophyll meter
1. Two two light LED lighting source, one is red (peak wavelength 650 nm), is a kind of infrared light (940 nm), two kinds of light through the blades, playing to the receiver, the light signal is converted into analog signals, the analog signal amplifier amplification, produced by the analog/digital converter is converted into digital signal, digital signal is processed by a microprocessor, calculate the SPAD value and display on the LCD screen.
2. Calibration and calculation of measurement value of chlorophyll meter
(1) in the calibration process, the pressure head is not included in the sample, and the two leds are illuminated in turn, and the received light is converted into electrical signals, and the ratio of the intensity of light is used to calculate.
(2) after the sample is clamped in the head, the two leds again emit light, and the light transmitted through the blade is transferred to the receiver, which is converted into an electrical signal, and the intensity ratio of the transmission light is calculated.
3) the value of step 1 and 2 is used to calculate the measurement value of the SPAD, i.e. the relative content of the current chlorophyll in the sample blade.
Technical indicators
1. Measurement of chlorophyll: 0.0-99.9 SPAD nitrogen content: 0.0-99.9 mg/g
Leaf humidity: 0.0-99.9 RH % leaf temperature: - 10-99.9 ºC
2. Measuring area 2mm * 2mm
3. Measurement precision chlorophyll: within the unit of SPAD (at room temperature, the SPAD value is between 0-50)
Nitrogen content: plus or minus 5% foliar humidity: plus or minus 5% foliar temperature: plus or minus 0.5 ºC
4. Reproducibility chlorophyll: less than 0.3 SPAD (SPAD value is between 0 and 50)
Nitrogen content: + / - 0.5 unit/humidity: + / - 0.5 unit leaf temperature: plus or minus 0.2 ºC
5. Time interval is less than 3 seconds
6. Data storage capacity of 32KB
7. Power supply 4.2 V rechargeable lithium battery
8. Battery capacity 2000mah
Weight 200g
10. Work and storage environment - 10 ºC to 50 ºC relative humidity of 85% or less