Frequently Asked Questions about the KONICA MINOLTA SPAD-502Plus Chlorophyll Meter:

1/ What is the SPAD-502Plus Chlorophyll Meter?

The SPAD-502Plus is a handheld, non-destructive meter for measuring the relative chlorophyll content of crop leaves in the field, helping optimize fertilizer use and monitor plant health.

2/ Which crops can be measured?

It’s widely used on wheat, rice, corn, cotton and many other agricultural and horticultural plants to assess nitrogen status and overall vigor.

3/ How does the SPAD-502Plus determine chlorophyll content?

It measures optical density at two wavelengths - red (600 - 700nm) and near-infrared (~950 nm) - and calculates a SPAD value proportional to leaf chlorophyll.

4/ What is the measurement range and area?

The display range is -9.9 to 199.9 SPAD units, with a 2 x 3mm measurement aperture and a maximum leaf thickness of 1.2mm.

5/ What level of accuracy and repeatability does it offer?

Accuracy is +/-1.0 SPAD (0 - 50 SPAD), repeatability +/-0.3 SPAD (0 - 50 SPAD), and reproducibility +/-0.5 SPAD, ensuring reliable readings across multiple measurements.

6/ What light source and sensor does it use?

It employs two LED light sources and a silicon photodiode receptor to capture transmitted light intensity.

7/ What display and memory functions are available?

An LCD shows a four-digit SPAD value (to one decimal place), the number of measurements, and a trend graph of stored data. Memory holds up to 30 readings and can calculate their average automatically.

8/ What are its physical characteristics?

The meter is compact and lightweight for portability. It meets water-resistance rating IPX-4, allowing use in light rain (not immersible).

9/ How do I perform a measurement?

- Install two AA-size alkaline batteries.

- Power on the device.

- Clamp the leaf between the sensor heads and close gently.

- Read the SPAD value on the LCD.

- Press the save button if recording the value.

10/ How fast can I take consecutive readings?

The minimum interval between measurements is approximately 2 seconds, enabling rapid data collection in the field.

11/ What is the power source and battery life?

It runs on two AA batteries, providing over 20000 measurements under test conditions with new alkaline cells.

12/ How should I clean and care for the meter?

Wipe the exterior and sensor surfaces with a dry or slightly damp cloth. Do not immerse in water or spray solvents directly onto the instrument.

13/ How do I check or calibrate its performance?

Use the supplied reference checker plate to verify measurement stability. If readings deviate from the standard, refer to the maintenance manual or contact service support - QTE Technologies (qtetech.com/en)

14/ How does SPAD data optimize fertilization?

By correlating SPAD values with leaf nitrogen content, growers can time and dose nitrogen applications precisely, often reducing usage by 20 - 40% without yield loss.

15/ Can it detect nutrient deficiencies other than nitrogen?

While mainly tracking chlorophyll (and thus nitrogen), SPAD trends can signal general stress or chlorophyll-related issues, prompting broader nutrient or environmental assessments.

16/ Where can I purchase the SPAD-502Plus?

Please contact QTE Technologies (qtetech.com/en).

17/ What accessories are included or optional?

Standard kit includes AA batteries, a leaf-insertion stopper, reference checker plate, carrying case, and instruction manual. Optional extras may include spare stopper sets and protective covers.