• 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

The SPAD 502 Plus Chlorophyll Meter instantly measures chlorophyll content or “greenness” of your plants to reduce the risk of yield-limiting deficiencies or costly overfertilizing. The SPAD 502 Plus quantifies subtle changes or trends in plant health long before they’re visible to the human eye. Non-invasive measurement; simply clamp the meter over leafy tissue, and receive an indexed chlorophyll content reading (0-99.9) in less than 2 seconds. Assess nitrogen needs by comparing in-field SPAD readings to university guidelines or to adequately fertilized reference strips. Research shows a strong correlation between SPAD measurements and leaf N content.

New features in the SPAD 502 Plus include:
• Trend graphing stores and displays up to 30 measurements
• Waterproof design

The SPAD 502 Plus meter can be purchased with or without a built-in data logger. The data logging version (Item 2900PDL) allows you to compile readings for statistical analysis. Includes an RS-232 port for communicating with a PC* and/or portable GPS receiver**. Use geo-referenced data to correlate N measurements to yield maps or download the data into mapping software. This robust field-data collection device has a capacity of 1,488 measurements when coupled with a GPS receiver or 4,096 measurements when used without GPS. Requires software running on Windows 98 or higher. GPS/DGPS cable required for geo-referenced operation.