GENEQ > Environment > Plant Analysis

Chlorophyll Meter
Model SPAD-502


A lightweight Handheld meter for measuring the chlorophyll content of leaves without causing damage to plants. The SPAD-502 is a compact meter designed to help users improve crop quality and increase crop yeild by providing an indication of the amount of chlorophyll present in plant leaves. The amount of chlorophyll content of plant leaves is related to the condition of the plant, and thus can be used to determine when additional fertilizer is necessary. By optimizing nutrient conditions, healthier plants can be grown, resulting in a larger crop yeild of higher quality.

FEATURES
  • Compact and lightweight for portability. The SPAD-502 is small enough to fit in a pocket and is extremely lightweight (only 225g) so it can be easily taken anywhere.
  • Quick, easy measurement. Measurements are taken by simply inserting a leaf and closing the measuring head. It is not necessary to cut the leaf, so the same leaf can be measured throughout the growing process.
  • Water-resistant. The SPAD-502 is water-resistant, so it can be used outside even in the rain. It is not immersible and should not be cleaned with water.
  • Low power consumption. The SPAD-502 uses LED light sources, resulting in extremely low power consumption. One set of two AA size alkaline manganese batteries can provide approximately 20,000 measurements
  • Small measuring area. The measuring area is only 2 x 3 mm, allowing measurement of even small leads. A sliding depth stop is included for accurate positionning of sample leaves.
  • High accuracy. High measuring accuracy (±1.0 SPAD unit for rice-plant leaves) allows close examination of growing conditions.
  • Data memory. The SPAD-502 has memory space for 30 measurements. Data in memory can be recalled or deleted at a later time, and the average value of all data memory can be automatically calculated.
  • Reading checker. A reading checker enables users to check that the SPAD-502 is functioning correctly and providing accurate readings

APPLICATIONS
Checking the nutritional condition of plants
The chlorophyll present in the plant is closely related to the nutritional condition of the plant. For a particular plant species, a higher SPAD value indicates a healthier plant.
Determining when additional fertilizer is necessary
A decrease in the SPAD value indicates a decrease in the chlorophyll content and nitrogen concentration. This decrease may be due to a lack of nitrogen available in the soil. This problem can be solved by adding fertilizer to the soil. For example, it was determined from past experience that for Sasanishiki rice plants a SPAD value of 35 or above was desirable to produce target yield of 600kg/10a. During the differentiation and formation of ears, a period of rapid plant development, the SPAD value fell to between 29 and 32, indicating thant additional fertilizer was necessary.

SPECIFICATIONS
Type Handheld meter for measuring chlorophyll using optical density difference at two wavelengths
Measurement Sample Crop leaves
Measurement System Optical density difference at two wavelengths
Measurement Area 2 x 3 mm
Light Source 2 LED's (light emitting diodes)
Receptor 1 SPD (sillicon photodiode)
Display Measurement data: 3 digits LCD with decimal point
Data number: 2 digits with LCD
Data Memory Space for 30 data sets
Controls Power switch, average key, all data delete key, one data delete key, and data recall key
Power Source 2 AA size alkaline manganese (1.5V) batteries
Battery Life More than 20,000 measurements
Min. Interval Between Measurements Less than 2 seconds
Accuracy With in +/-1.0 SPAD unit (at room conditions, SPAD value between 0 and 50)
Repeatability Within +/-0.3 SPAD units (SPAD value between 0 and 50)
Reproducibility Within +/- 0.5 SPAD units (SPAD value between 0 and 50)
Temp. Drift Less than +/-0.4 SPAD units/°C
Temp. Range Operation: 0 to 50°C
Storage: -20 to +55°C
Dimensions 14 x 78 x 49 mm (6-7/16 x 3-1/16 x 1-15/16 in.)
Weight 225g not including batteries
Other Warning buzzer
User calibration function

CAT. NO. DESCRIPTION
MISPAD502- chlorophyll meter SPAD-502