NBL-S-TMC-8 8-in-1 Soil Integrated Sensor

The NiuBoL NBL-S-TMC-8 is an 8-in-1 soil multi-parameter sensor designed to measure soil temperature, moisture, electrical conductivity (EC), salinity, pH and nitrogen, phosphorus and potassium (NPK) reference values through one RS485 Modbus RTU interface.

The sensor is suitable for smart agriculture, irrigation, greenhouse cultivation, soil research, field experiments and IoT monitoring projects where several soil parameters need to be collected from the same monitoring point.

Important: The integrated NPK and pH channels are intended mainly for field reference and trend monitoring. NPK values are derived from soil electrical characteristics and empirical coefficients, while the integrated pH channel is less accurate than a dedicated glass-electrode pH sensor.

What Does the 8-in-1 Soil Sensor Measure?

NBL-S-TMC-8 Technical Specifications

Note: the pH and NPK channels are intended mainly for field reference and trend monitoring. For higher-accuracy pH measurement, use a dedicated glass-electrode soil pH sensor. For actual nutrient quantification, laboratory analysis is recommended.

Why Choose an 8-in-1 Soil Sensor?

The main advantage of an integrated soil sensor is that several parameters can be measured at one location using one probe, one power connection and one RS485 interface.

Compared with installing several separate sensors, this can reduce:

• Number of probes

• Field wiring

• Installation time

• RS485 network complexity

• Data-logger input requirements

• Maintenance points

The 8-in-1 model is particularly useful when salinity data is required in addition to the parameters available from the 7-in-1 version.

Understanding the NPK Values

The NBL-S-TMC-8 does not perform laboratory chemical analysis of nitrogen, phosphorus and potassium.

The NPK values are derived from soil electrical characteristics and empirical coefficients. Soil moisture, EC, salinity, fertilizer concentration, soil texture and environmental conditions can therefore affect the displayed values.

The NPK channels are most useful for:

• Trend monitoring over time

• Relative comparison between monitoring points

• Rapid field observation

• IoT data collection

For accurate fertilizer formulation or actual soil nutrient concentration, laboratory analysis should be used.

Understanding the Integrated pH Measurement

The integrated pH channel provides convenient field reference data, but the sensor manual states that pH values should mainly be used as a reference.

If higher pH accuracy is required, use a dedicated glass-electrode soil pH sensor.

What Does the Salinity Channel Mean?

The salinity channel provides a reference value related to the electrical conductivity of the soil environment. It is useful for observing changes in soil salt conditions, particularly in irrigated agriculture, greenhouses and saline-soil monitoring.

The salinity value should be interpreted together with EC, soil moisture and irrigation conditions because these parameters are closely related.

How to Install the 8-in-1 Soil Sensor

Quick Measurement

Select a representative location and avoid stones or other hard objects. Insert the probe vertically into the soil and ensure that the sensing rods maintain close contact with the surrounding soil.

Do not repeatedly move the probe from side to side during insertion because this can create air gaps and reduce measurement consistency.

Long-Term Buried Measurement

For long-term monitoring, dig a pit to the required depth and insert the sensor horizontally into the undisturbed soil wall. Backfill and compact the soil so the electrodes remain in close contact with the soil.

After the measurement point stabilizes, the sensor can provide continuous data over extended periods.

RS485 Modbus Communication

The NBL-S-TMC-8 provides all eight measurement channels through one RS485 Modbus RTU connection.

8-in-1 Soil Sensor → RS485 Modbus → PLC / Data Logger → 4G / Ethernet / LoRaWAN Gateway → MQTT / HTTP → Cloud or Private Server

The default communication configuration is 9600 baud, 8 data bits and no parity. The recommended interval between two communications is at least 1000 ms.

RS485 Wiring

Multiple Sensors on One RS485 Bus

Multiple NBL-S-TMC-8 sensors can share one RS485 bus when each sensor has a unique Modbus address.

• Assign a unique address to every sensor.

• Use twisted-pair cable for RS485 communication.

• Use daisy-chain wiring where practical.

• Check power-voltage drop on long cable runs.

• Use a suitable centralized DC power supply.

• Add RS485 termination according to cable length and field conditions.

IoT and Remote Monitoring

The 8-in-1 sensor can be integrated with 4G or LoRaWAN data-acquisition equipment for distributed agricultural monitoring.

8-in-1 Sensor → RS485 → IoT Gateway → 4G / LoRaWAN → MQTT / HTTP → Customer Server

For LoRaWAN projects, the RS485 sensor normally connects to a compatible RS485-to-LoRaWAN node rather than communicating wirelessly by itself.

Typical Applications

• Smart agriculture

• Automatic irrigation

• Greenhouse cultivation

• Flowers and vegetables

• Grassland and pasture monitoring

• Soil research

• Plant cultivation

• Saline-soil monitoring

• Remote IoT soil-monitoring systems

7-in-1 vs 8-in-1 Soil Sensor

Choose the 8-in-1 model when salinity is required in addition to temperature, moisture, EC, pH and NPK reference monitoring. If salinity is not required, the 7-in-1 version may be sufficient.

8-in-1 Soil Sensor FAQ

Q1. What does the 8-in-1 soil sensor measure?

A1. It measures soil temperature, moisture, EC, salinity and pH, and provides nitrogen, phosphorus and potassium reference values.

Q2. What is the difference between the 7-in-1 and 8-in-1 sensor?

A2. The 8-in-1 version adds a salinity channel. The other main monitored parameters are similar.

Q3. Are the NPK values laboratory accurate?

A3. No. NPK values are empirical field-reference values derived from soil electrical characteristics. Laboratory analysis is recommended for actual nutrient quantification.

Q4. Is the integrated pH measurement highly accurate?

A4. The integrated pH channel is mainly suitable for reference monitoring. For higher pH accuracy, use a dedicated glass-electrode soil pH sensor.

Q5. Can the sensor remain buried for long-term monitoring?

A5. Yes. The sensor manual provides a buried measurement method for long-term monitoring when the probe is installed correctly and maintains close contact with the soil.

Q6. Can the sensor connect directly to a PLC?

A6. Yes. The sensor uses RS485 Modbus RTU and can connect to compatible PLCs, RTUs and data loggers.

Q7. Can several 8-in-1 sensors share one RS485 bus?

A7. Yes. Each sensor should use a unique Modbus address, and the RS485 wiring and power supply must be designed correctly.

Q8. Can the sensor data be transmitted through LoRaWAN?

A8. Yes. The RS485 sensor can connect to a compatible RS485-to-LoRaWAN node and gateway.

Q9. Can this sensor directly detect soil pollution?

A9. No. It does not directly identify heavy metals, pesticides or other pollutants. It measures soil physical and electrical parameters plus reference pH and NPK values.

Q10. What information is needed for quotation?

A10. Provide the quantity, cable length, monitoring depth, number of points, communication method and whether a data logger, LoRaWAN node, 4G gateway or solar power system is required.

8-in-1 Soil Sensor Datasheet

1. NBL-S-TMC-8 8-in-1 Soil Integrated Sensor Instruction Manual

8-in-1-Soil-Composite-Sensor-Manual.pdf

Request an 8-in-1 Soil Sensor Quotation

For quotation and system selection, provide the required quantity, cable length, installation depth, number of monitoring points and whether the sensors will connect to a PLC, data logger, LoRaWAN node, 4G gateway or private server.

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