4-in-1 Soil Moisture Temperature EC and Salinity Sensor for Smart Irrigation

The JW-TM4 4-in-1 Soil Moisture EC Salinity Sensor is an integrated soil monitoring probe designed to measure four important soil parameters: volumetric water content (VWC), soil temperature, electrical conductivity (EC), and salinity.

Featuring Frequency Domain Reflectometry (FDR) technology for soil moisture measurement, 316 stainless steel probes, IP68 protection, and multiple optional signal outputs, the JW-TM4 is suitable for precision agriculture, greenhouse cultivation, smart irrigation, soil monitoring stations, and agricultural research.

The sensor helps agricultural system integrators and growers monitor soil water conditions and electrical conductivity within a single measurement point.

1. Product Overview

What Is a 4-in-1 Soil Moisture EC Salinity Sensor?

A 4-in-1 soil sensor combines multiple soil measurements into one integrated sensing device.

The JW-TM4 measures:

1. Soil Moisture: The volume of water contained in a given volume of soil.
2. Soil Temperature: Temperature conditions around the installed sensor.
3. Soil Electrical Conductivity: The electrical conductivity associated with soil conditions and dissolved ions.
4. Soil Salinity: A salinity-related measurement that can be used to observe changes in soil salt conditions.

Together, these measurements provide useful information for evaluating root-zone conditions, planning irrigation, and observing changes associated with fertilization and salt accumulation.

Unlike a basic soil moisture sensor, the JW-TM4 provides EC and salinity information alongside water content and temperature.

For additional sensor options, explore the JW-IoT Soil Sensors Collection.

2. Four Soil Parameters in One Sensor

2.1 Soil Moisture Measurement – 0–60% VWC

Soil moisture is one of the key parameters used in irrigation management.

The JW-TM4 uses Frequency Domain Reflectometry (FDR) technology to evaluate soil water content based on differences in the dielectric properties of soil constituents.

Because water has significantly different dielectric properties from most mineral soil components, changes in the soil dielectric response can be used to estimate volumetric water content.

Measurement specifications:

• Range: 0–60% VWC
• Resolution: 0.1%
• Accuracy: ±3% within 0–35% VWC
• Accuracy: ±5% within 35–60% VWC

Soil moisture readings can support irrigation scheduling, soil water trend analysis, and evaluation of changes following rainfall or irrigation events.

Actual measurement performance depends on soil conditions, probe installation, and the suitability of the sensor for the measurement medium.

2.2 Soil Temperature Measurement – -40°C to +80°C

Soil temperature influences root-zone conditions, biological activity, and the movement of water and nutrients in agricultural soils.

The JW-TM4 integrates a thermistor-based temperature sensing element for soil temperature monitoring.

Measurement specifications:

• Range: -40°C to +80°C
• Accuracy: ±0.5°C
• Resolution: 0.1°C

By combining temperature and moisture measurements, users can observe environmental changes at the installed soil depth.

These measurements may be incorporated into greenhouse monitoring, agricultural field observations, and research data collection.

2.3 Soil Electrical Conductivity Measurement – 0–20,000 μS/cm

Soil electrical conductivity is associated with the presence and movement of dissolved ions and can provide information about changes in soil conditions.

The JW-TM4 measures electrical conductivity within a specified range of 0–20,000 μS/cm.

Measurement specifications:

• Range: 0–20,000 μS/cm
• Accuracy: ±5%
• Resolution: 1 μS/cm

EC monitoring can be useful for observing changes associated with irrigation water, fertilizer applications, and salinity conditions.

However, soil EC is influenced by several factors, including water content, temperature, and soil composition.

EC readings should not be interpreted as direct measurements of individual nutrient concentrations such as nitrogen, phosphorus, or potassium.

Users requiring nutrient-specific information should select additional sensors or laboratory testing methods appropriate to their application.

2.4 Soil Salinity Measurement – 0–10,000 mg/L

Excessive salt accumulation in the root zone can affect plant water uptake and agricultural productivity.

The JW-TM4 provides soil salinity-related readings alongside soil moisture, temperature, and EC data.

Measurement specifications:

• Range: 0–10,000 mg/L
• Accuracy: ±5%
• Resolution: 1 mg/L

Salinity monitoring can support long-term observation of soil conditions in irrigation and cultivation projects.

For reliable interpretation, users should consider soil type, moisture conditions, and suitable reference measurements.

The salinity output should not automatically be treated as equivalent to laboratory-measured saturated-paste extract salinity or a direct measurement of total salt mass in soil.

3. Technical Specifications

Measurement Parameters

Electrical and Mechanical Specifications

Configuration Note: Power supply and signal output options depend on the selected sensor version. Please confirm the required electrical configuration before ordering.

4. Applications of the JW-TM4 Soil Sensor

4.1 Precision Agriculture and Smart Irrigation

The JW-TM4 provides soil moisture and temperature measurements together with conductivity and salinity-related information.

For smart irrigation projects, the sensor can be used to monitor soil conditions at selected locations and support data-informed irrigation planning.

Typical applications include:

• Agricultural irrigation monitoring
• Soil water trend analysis
• Field moisture observation
• Irrigation evaluation
• Long-term soil condition monitoring

Sensor data may be collected by compatible external monitoring equipment for analysis or irrigation decision support.

4.2 Greenhouse Soil Monitoring

Greenhouse crop production requires attention to root-zone conditions.

The JW-TM4 can be deployed in suitable soil-based greenhouse growing systems to monitor:

• Root-zone soil moisture
• Soil temperature fluctuations
• Electrical conductivity changes
• Salinity-related trends

The measurements can help greenhouse operators compare conditions before and after irrigation or fertilization.

For greenhouse projects requiring only moisture, temperature, and EC measurements, JW-IoT also offers the Soil Moisture EC Temperature Probe for Precision Farming.

4.3 Soil Salinity Monitoring in Agricultural Fields

Salinity management is an important concern in agricultural areas affected by saline irrigation water, insufficient drainage, or salt accumulation.

The JW-TM4 can provide EC and salinity-related trend data for suitable soil conditions.

However, accurate absolute moisture measurement in highly saline or alkaline soils may require an alternative sensor or additional calibration.

Before deployment in strongly saline soils, the suitability of the measurement technology should be evaluated.

4.4 Agricultural Research and Field Experiments

The JW-TM4 may be used in research projects requiring concurrent measurements of soil moisture, temperature, EC, and salinity.

Possible applications include:

• Irrigation experiments
• Soil water dynamics studies
• Crop cultivation research
• Soil condition monitoring
• Agricultural demonstration projects

When used in research, sensor measurements should be validated against appropriate reference methods according to the required accuracy.

4.5 Grassland, Horticulture, and Vegetable Cultivation

The integrated sensor can be used in suitable soil environments for monitoring water and temperature conditions in grassland, vegetable cultivation, and horticultural applications.

Monitoring multiple soil parameters allows users to assess changes in the growing environment without installing a separate sensing device for every parameter.

5. FDR Soil Moisture Measurement Technology

The JW-TM4 uses Frequency Domain Reflectometry for volumetric soil moisture measurement.

FDR is a dielectric measurement approach in which the response of an electromagnetic field is related to the dielectric properties of the surrounding medium.

Because soil water strongly influences this response, the measurement can be used to estimate volumetric water content.

Benefits of FDR-Based Soil Monitoring

• Provides volumetric water content readings.
• Supports repeated measurements at a fixed monitoring point.
• Enables monitoring of wetting and drying trends.
• Can be integrated with electrical soil monitoring equipment.
• Is suitable for agricultural monitoring when the soil and calibration conditions match the sensor’s intended operating conditions.

FDR readings can be affected by soil properties, salinity, temperature, and installation quality. Users should therefore evaluate the sensor against the intended soil conditions before relying on absolute readings.

For a broader comparison of moisture measurement methods, see the Soil Moisture Sensor Buying Guide 2026.

6. Signal Outputs and Monitoring System Integration

The JW-TM4 is offered with different electrical output configurations to match agricultural monitoring equipment.

Available output types include:

Output availability depends on the ordered configuration.

Integration with Agricultural Monitoring Systems

A typical monitoring arrangement may include:

JW-TM4 Soil Sensor → Compatible Data Logger or RTU → Communication Network → Monitoring Platform

The sensor measures soil conditions, while an external data logger or monitoring controller handles data acquisition, storage, or transmission according to the system design.

For a larger agricultural monitoring project, users may combine multiple soil measurement points with compatible external data collection equipment.

Communication settings, wiring diagrams, data registers, and output scaling should be confirmed for the selected version before system integration.

The JW-TM4 itself should not be confused with a wireless data logger or a standalone cloud monitoring station.

7. Installation Guidelines

Proper installation is important for obtaining representative soil measurements.

Recommended Installation Procedure

1. Select the Measurement LocationChoose a position representative of the intended field or root-zone monitoring area.
2. Determine the Installation DepthSelect the target soil depth according to crop characteristics and monitoring objectives.
3. Prepare the Soil PitExcavate a small pit to the selected depth.
4. Position the Sensor HorizontallyPlace the sensor with its probes in a horizontal orientation at the measurement depth.
5. Establish Good Soil ContactCover the probes with fine soil and carefully compact the surrounding soil to reduce air gaps.
6. Backfill the PitRestore the excavated soil while keeping the sensor in its intended position.
7. Connect the SensorComplete wiring according to the electrical configuration and verify the connections before applying power.
8. Check the Measurement DataVerify that sensor readings are reasonable for the actual soil conditions.

Important Installation Precautions

• Do not connect wiring while power is applied.
• Do not disassemble or modify the sensor without technical approval.
• Avoid contact with sharp objects or corrosive liquids that could damage the sensing surfaces.
• Do not arbitrarily modify the cable length.
• Frozen soil conditions can produce inaccurate moisture readings.
• Highly saline soils, sandy soils, and powder-like materials may require alternative calibration or sensing methods for absolute moisture measurement.

8. Laboratory Calibration and Measurement Verification

9. JW-TM4 vs. Standard 3-in-1 Soil Sensors

The JW-TM4 is intended for projects that require a four-parameter soil monitoring configuration.

Some three-parameter soil sensors can also report calculated salinity values through their digital interface, so the differences between models should be assessed using actual specifications rather than parameter count alone.

Explore additional options in the JW-IoT Soil Sensors category.

10. Request a Quote – JW-TM4 Soil Moisture EC Salinity Sensor

Looking for a multi-parameter soil sensor for an irrigation, greenhouse, or agricultural monitoring project?

JW-IoT offers the JW-TM4 4-in-1 Soil Moisture Temperature EC and Salinity Sensor for system integration and agricultural monitoring applications.

Contact our team to discuss:

• Required sensor quantity
• Digital or analog output configuration
• Power supply requirements
• Soil type and measurement environment
• Cable requirements
• Data logger or monitoring system compatibility

Contact JW-IoT for JW-TM4 specifications, configuration details, and a quotation.

Explore more Soil Monitoring Sensors for precision agriculture and smart irrigation projects.