CHLOROPHYLL METER

SPAD-502Plus
A lightweight handheld meter for measuring the chlorophyll content of leaves without causing damage to plants.
The SPAD-502Plus is a compact meter
designed to help users improve crop quality and increase crop yield by providing an indication of the amount of chlorophyll present in plant leaves. The 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 yield of higher quality.

Theory

The SPAD-502Plus determines the relative amount of chlorophyll present by measuring the absorbance of the leaf in two wavelength regions. The graph below shows the spectral absorbance of chlorophyll extracted from two leaf samples using 80% acetone. From the diagram, it can be seen that chlorophyll has absorbance peaks in the blue (400-500 nm) and red (600-700 nm) regions, with no absorbance in the near-infrared region. To take advantage of this characteristic of chlorophyll, the SPAD502Plus measures the absorbances of the leaf in the red and near-infrared regions. Using these two absorbances, the meter calculates a numerical SPAD value which is proportional to the amount of chlorophyll present in the leaf.
Checking the nutritional condition of plants
The chlorophyll present in the plant leaves is closely related to the nutritional condition of the plant. As can be seen from the graph below, the chlorophyll content (represented by the measured SPAD value) will increase in proportion to the amount of nitrogen (an important plant nutrient) present in the leaf. For a particular plant species, a higher SPAD value indicates a healthier plant.
Leaf-blade nitrogen concentration
3.3 3.1 2.9 2.7 2.5 2.3 2.1 1.9 1.7
y =0.079 x - 0.154 r =0.908*** n =68

Absorbance

1984 1985

700(nm)

Measured SPAD value

Ultraviolet

Wavelength

Infrared

Wheat, Rice, Corn, Cotton and beyond
The SPAD-502Plus serves in a wide variety of plant applications. Through its history, the SPAD series has established itself as a leading brand in chlorophyll measurement across the world. It has been serving researchers and growers, enabling them to perform field tests quickly and easily. The SPAD series has been used for various kinds of plants and its applications are still growing.
Features Trend graph display
Changes in measurement data over time can be seen, and abnormal values can be noticed at a glance.

Data memory

The SPAD-502Plus 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 in memory can be automatically calculated.
Memory data count Average Error message
Compact and lightweight for portability
The SPAD-502Plus is small enough to fit in a pocket and is extremely lightweight (only 200 g) so it can be easily taken anywhere.

Quick, easy measurements

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.

N= AVG

Measuring head Measurement center line

Reading checker

A reading checker enables users to check that the SPAD-502 is functioning correctly and providing accurate readings.

Water-resistant

The SPAD-502Plus is water-resistant (IPX-4), so it can be used outside even in the rain.
*It is not immersible, and should not be cleaned with water.

Names of parts

Depth stop Receptor window

Low power consumption

The SPAD-502Plus uses LED light sources, resulting in extremely low power consumption. One set of two AAsize alkaline-manganese batteries can provide approximately 20,000 measurements.

Press here to close.

Power switch

Small measuring area

The measuring area is only 2 x 3 mm, allowing measurements of even small leaves. A sliding depth stop is included for accurate positioning on sample leaves.
Display ALL DATA CLEAR button AVERAGE button Battery-chamber cover

High accuracy

High measuring accuracy ( 1.0 SPAD unit for rice-plant leaves) allows close examination of growing conditions.
1 DATA DELETE button DATA RECALL button

Nitrogen management

Nitrogen (N) management is a very important issue for plant growers and for the environment. For growers, knowing the N requirement of plant enables the proper amount of N fertilizer supply to be managed. Some experiments show that the SPAD series contributed to reductions in the use of N fertilizer by tens of percents with no loss in yield. By optimizing the N fertilization efficiency in the field, proper N fertilizer management reduces the possiblity of excessive supply of fertilizer, which can cause diseases in plants and environmental contamination. There is increasing awareness of the need for applying the proper amount of N fertilizer in respect to water contamination in both flowing streams and underground water due to nutrient leaching through the field's soil. The SPAD series is playing a significant role in day to day development of N fertilizer application techniques.

Cotton

Specifications
Type Measurement subject Measurement method Measurement area Subject thickness Subject insertion depth Light source Receptor Display Display range Memory function Power source Battery life Minimum interval between measurements Accuracy Repeatability Reproducibility Temperature drift Operating temperature/humidity range Storage temperature/humidity range Size; Weight Other Standard accessories Chlorophyll Meter SPAD-502Plus Crop leaves Optical density difference at 2 wavelengths 2 mm3 mm 1.2 mm maximum 12 mm (with stopper having position adjustable from 0 to 6 mm) 2 LED elements 1 SPD (silicon photodiode) LCD panel showing 4-digit measurement value (values shown to first decimal place) and 2-digit number of measurements; Trend graph of values in memory can also be shown. -9.9 to 199.9 SPAD units Memory capacity for up to 30 values; Calculation/display of average of data in memory also possible 2 AA-size alkaline batteries More than 20,000 measurements (when using new alkaline batteries under Konica Minolta test conditions) Approx. 2 seconds Within 1.0 SPAD units (for SPAD value between 0.0 and 50.0 under normal temperature/humidity) * added to display when measurement exceeds 50.0 SPAD units Within 0.3 SPAD units For SPAD value between 0.0 and 50.0 (with no change in sample position) Within 0.5 SPAD units Within 0.04 SPAD units/C 0 to 50C; Relative humidity of 85% or less (at 35C) with no condensation -20 to 55C; Relative humidity of 85% or less (at 35C) with no condensation 78 (W) 164 (H) 49 (D) mm, 200 g (excluding batteries) Warning buzzer; User compensation factor Depth stop; Strap; 2 AA-size alkaline batteries; Soft case; Reading checker
SPAD value: Index value displayed by Konica Minolta Chlorophyll meters and having a correlation to chlorophyll density. Specifications and appearance subject to change without notice.

Dimensions

(Units: mm)

SAFETY PRECAUTIONS

For correct use and for your safety, be sure to read the instruction manual before using the instrument.
Be sure to use the specified battery. Using improper
battery may cause a fire or electric shock.
Registration No. : YKA 0937154 Registration No. : JQA-E-80027 Registration date : March 3, 1995 Registration date : March 12, 1997
2009 KONICA MINOLTA SENSING,INC.

9242-4856-10 AJKAPK 1

Printed in Japan

A Comparison of Opti-Sciences CCM-200 Chlorophyll Meter and the Minolta SPAD 502 Chlorophyll Meter
Nick Knighton and Bruce Bugbee Crop Physiology Laboratory-Utah State University Introduction Handheld chlorophyll meters are an easy way to non-destructively estimate chlorophyll content of leaves. The chlorophyll meters in this study both measure ratios of radiation transmitted through the leaf at two wavelengths. The SPAD measures the RVI (Ratio Vegetative Index) at 940 nm and 650 nm while the CCM-200 uses 940 nm and 660 nm. The leaf area measured by each handheld meter also differs. The SPAD 502 measures a 0.06 cm2 area while the CCM200 a 0.71 cm2 area. Materials and Methods Measurements were taken using Minolta SPAD 502 and Opti-Sciences CCM-200 handheld chlorophyll meters. Measurements were taken on Roscolux colored plastic filters (Figure 3) and then on leaves of a ficus benjamina tree. Plastic filters were used as leaf models because of their similarity to leaf spectra and their uniformity of color. SPAD data was then plotted against the CCM data and regressions were plotted. Results When plotted against SPAD measurements, CCM-200 showed a high second order correlation on plastic filters (Figure 4).

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80 y = 0.x - 0.x + 6.8 e-4 x n = 15 60

C alc o lo r 9 0

1 :1 M o ss G re en
L ight G re en T o ug h P lu s P ale C alc o lo r G re en G a slight 0 G re en T o ugh 1 /2 0
T urq u o ise P e a G ree n L ea f G re en C alc o lo r 20 C a lco lo r B lue G re en 40

C hro m a G ree n

Figure 4. Graph of SPAD measurements against CCM-200 measurements. The data shows a strong third order correlation. Measurements taken on ficus benjamina showed results similar to those taken on the plastic filters (Figure 5).
y = 0.4 x - 0.x 2 + 0.x 3 n = 50

F ic u s

P a p e r B irc h (R ic h a rd s o n , )
Figure 5. The relative chlorophyll content of ficus benjamina as measured by the SPAD 502 and the CCM-200. Paper Birch data generated from Richardson, 2002. Conclusion The Opti-Sciences CCM-200 chlorophyll meter and the Minolta SPAD 502 chlorophyll meter show a curvilinear relationship. Correlations done on plastic filters were similar to those done on actual leaves. Literature Cited Richardson, A. D., S. P. Duigan, G. P. Berlyn. 2002. And evaluation of noninvasive methods to estimate foliar chlorophyll content. New Phytologist. 153:185-194.

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