CHLOROPHYLL METER
SPAD-502Plus
A lightweight handheld meter for
measuring the chlorophyll content of
leaves without causing damage to plants.
NEW
Theory
400 500
Ultraviolet
Wavelength Infrared
600 700(nm)
Absorbance
A
B
3.5
3.3
3.1
2.9
2.7
2.5
2.3
2.1
1.9
1.7
24 26 28 30 32 34 36 38 40 42
Leaf-blade nitrogen concentration
y =0.079 x - 0.154
r =0.908
***
n =68
Measured SPAD value
1984
1985
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.
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.
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 eld tests
quickly and easily. The SPAD series has been used for various kinds of plants and its applications are still growing.
WheatCorn
Features
N=
30
AVG
35.8
Trend graph display
Changes in measurement data over time can be seen,
and abnormal values can be noticed at a glance.
Compact and lightweight for portability
The SPAD-502Plus is small enough to t 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.
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.
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.
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
Reading checker
A reading checker enables users to check that the SPAD-502 is
functioning correctly and providing accurate readings.
Names of parts
Depth stop
Receptor
window
Measuring head
Measurement center line
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.
High accuracy
High measuring accuracy (± 1.0 SPAD unit for rice-plant
leaves) allows close examination of growing conditions.
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 eciency in the eld, proper N fertilizer management reduces the possiblity of excessive supply of fertilizer,
Display
ALL DATA CLEAR button
AVERAGE button
DATA RECALL button
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 owing
streams and underground water due to nutrient leaching through the
eld's soil.
The SPAD series is playing a signicant role in day to day development of
N fertilizer application techniques.
Battery-chamber cover
1 DATA DELETE button
Rice Cotton
Specications
164
7849
Registration No. : YKA 0937154
Registration date : March 3, 1995
Registration No. : JQA-E-80027
Registration date : March 12, 1997
Type Chlorophyll Meter SPAD-502Plus
Measurement subject Crop leaves
Measurement method Optical density dierence at 2 wavelengths
Measurement area 2 mm×3 mm
Subject thickness 1.2 mm maximum
Subject insertion depth 12 mm (with stopper having position adjustable from 0 to 6 mm)
Light source 2 LED elements
Receptor 1 SPD (silicon photodiode)
Display
Display range -9.9 to 199.9 SPAD units
Memory function Memory capacity for up to 30 values; Calculation/display of average of data in memory also possible
Power source 2 AA-size alkaline batteries
Battery life More than 20,000 measurements (when using new alkaline batteries under Konica Minolta test conditions)
Minimum interval between measurements Approx. 2 seconds
Accuracy
Repeatability Within ±0.3 SPAD units
Reproducibility Within ±0.5 SPAD units
Temperature drift Within ±0.04 SPAD units/°C
Operating temperature/humidity range 0 to 50°C; Relative humidity of 85% or less (at 35°C) with no condensation
Storage temperature/humidity range -20 to 55°C; Relative humidity of 85% or less (at 35°C) with no condensation
Size; Weight 78 (W) ×164 (H) ×49 (D) mm, 200 g (excluding batteries)
Other Warning buzzer; User compensation factor
Standard accessories 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.
Specications and appearance subject to change without notice.
LCD panel showing 4-digit measurement value (values shown to rst decimal place) and 2-digit number of
measurements; Trend graph of values in memory can also be shown.
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
For SPAD value between 0.0 and 50.0 (with no change in sample position)
Dimensions
(Units: mm)
SAFETY PRECAUTIONS
For correct use and for your safety, be s ure to read the
instruction manual before using the instrument.
Be sure to use the speci fied batter y. Usi ng im proper
•
battery may cause a re or electric shock.
9242-4856 -10 AJKAPK Printed in Japan1©2009 KONICA MINOLTA SENSING,INC.
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