What is soil NPK sensor?

Soil NPK Sensor for Soil Nutrient in Agriculture - Renke

The soil nitrogen phosphorus and potassium sensor (also called soil NPK sensor) is suitable for detecting the content of nitrogen, phosphorus, and potassium in the soil, and judging the fertility of the soil by detecting the content of nitrogen, phosphorus, and potassium in the soil, thereby facilitating the systematic assessment of soil fertility. The stainless steel probe of the soil npk sensor can be buried in the soil for a long time and is resistant to long-term electrolysis, salt, and alkali corrosion. The shell is vacuum potted and completely waterproof. It can apply for the detection of alkaline soil, acid soil, substrate soil, seedling bed soil & coconut bran soil.

soil nitrogen phosphorus and potassium sensor features

1. Simple to use, few operation steps, fast measurement, no reagents, unlimited detection times.

2. High measurement accuracy, fast response speed, and good interchangeability.

3. The electrode is made of specially treated alloy material, which can withstand strong external impact and is not easy to damage.

4. Completely sealed, resistant to acid and alkali corrosion, and can be buried in soil for long-term dynamic testing.

5. The probe plug-in design ensures accurate measurement and reliable performance.

We offer five common soil sensors for you

Soil NPK sensor working principle

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soil nitrogen phosphorus and potassium sensor datasheet

Power supply5-30VDC
Maximum power consumption≤0.15W
Operating temperature-40~80℃

NPK parameters

Range0-1999 mg/kg(mg/L)
Resolution1 mg/kg(mg/L)
Response time≤1S
Protection gradeIP68
Probe material316 stainless steel
Sealing materialBlack flame-retardant epoxy resin
Default cable length2 meters, cable length can be customized
Output signalRS485/4-20ma/0-5v/0-10v

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soil nitrogen phosphorus and potassium sensor application

npk soil sensors are widely used in the detection of soil nitrogen, phosphorus, and potassium, precision agriculture, forestry, soil research, geological prospecting, plant cultivation, and other fields.


1.Do you have a wireless soil npk sensor?

Yes, we have a portable soil npk tester

2.How to use a soil npk sensor?

Our sensor can connect with your PLC, MCU, or directly connect to our soil data logger to read the value. We offer a free cloud platform for you.

3.How to download the soil npk sensor manual?

To prevent the leakage of patented technical parameters, please contact us to download the instructions.

How to use soil npk sensors

1.Quick Test Method

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Select a suitable measurement location, avoid rocks, ensure that the steel needle does not touch hard objects, throw away the surface soil according to the required measurement depth, maintain the original tightness of the soil below, hold the sensor vertically and insert it into the soil. Do not shake left and right. It is recommended to measure multiple times for average value within a small range of a measuring point.

2. Buried measurement method

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Dig a pit with a diameter> 20cm vertically, insert the sensor needle horizontally into the pit wall at a predetermined depth, and fill the pit tightly. After a period of stability, measurement and recording can be carried out for several days, months, or even longer.


1. All steel needles must be inserted into the soil during measurement.

2. Avoid strong sunlight directly shining on the sensor to cause excessive temperature. Pay attention to lightning protection in the field.

3. Do not bend the steel needle violently, pull the lead wire of the sensor forcefully, and do not hit or hit the sensor violently.

4. The sensor's protection grade is IP68, so the whole sensor can be soaked in water.

5. Due to the presence of radiofrequency electromagnetic radiation in the air, it is not suitable to stay in the air for a long time with electricity.