TECHNOLOGY

Advanced time-domain transmissometry technology

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Comparing TDT⁵ to Existing Soil Moisture Sensing Technologies

See how our patented Time Domain Transmissometry (TDT⁵) advances beyond traditional soil moisture sensing technologies.

TDT⁵ Technology

Patented antenna design eliminates reflections

Advanced filtering removes EMI interference

Uniform accuracy across entire 75cm profile

Integrated design reduces costs

Transmission-based precision

Traditional TDR

Reflection-based measurement

Limited by wave reflection inconsistencies

Sensitive to electromagnetic interference

Point measurement accuracy varies

Higher manufacturing complexity

Conventional TDT

Transmission-based measurement

Measures pulse travel time through a transmission line

More stable than TDR with fewer reflection errors

Accuracy limited by short antenna length

Reduced performance in heterogeneous soils

FDR (Frequency Domain Reflectometry)

Resonance-based measurement

Determines moisture from oscillation frequency changes

Moderate accuracy but sensitive to soil salinity

Requires frequent recalibration

Typically measures at a single point

Capacitance Sensors

Dielectric-based measurement

Measures soil’s dielectric constant using an electric field

Low-cost and simple installation

Highly sensitive to air gaps and temperature

Limited precision and long-term stability

Sensor Technology Comparison

See how TDT⁵ compares to other soil moisture measurement technologies across key performance metrics.

Technology
Measurement Principle
Accuracy
Multi-Depth Capability
Noise Resistance
Technology
TDR
Wave Reflection Timing
Moderate
No
Low
High
TDT
Wave transmission timing
High
Limited
Medium
Moderate
TDT⁵
Patented extended TDT
Very High (±0.5% VWC)
Yes
Very High
Low
FDR
Frequency resonance
Moderate
No
Low
Moderate
Capacitance
Dielectric constant
Low–Moderate
No
Low
High
Technology

A Deeper Understanding

TDT⁵ measures soil moisture at multiple depths so you can understand what is happening throughout the entire soil profile. Each 15 cm segment provides a clear view of infiltration, root activity, and water movement. Instead of a single shallow reading, you get detailed moisture insight from the surface to the root zone.

Track irrigation and rainfall as they move through the soil

Detect dry zones before they create stress

Identify compaction layers and restricted root growth

Understand root activity at different depths

See deep percolation losses that single-depth sensors miss

Learn more

The TDT⁵ Measurement Process

400,000 pulses per measurement deliver ±1% repeatability across the entire soil profile.

01

Pulse Transmission

TDT⁵ converts the change in travel-time behavior into volumetric water content, using the sensor’s voltage response to shifts in the soil’s dielectric properties. This produces stable, repeatable readings that represent true soil moisture levels.

02

Signal Interaction

TDT⁵ interprets changes in the pulse’s effective travel-time behavior by measuring voltage shifts caused by dielectric changes in the soil. These voltage-based measurements are converted into reliable volumetric moisture readings.

03

Moisture Calculation

TDT⁵ converts the measured travel time into volumetric water content, producing stable, repeatable readings that reflect the soil’s true moisture levels.

Three Soil Calibration Types

TDT⁵ technology adapts to different soil conditions with three specialized calibration algorithms for maximum accuracy across all soil types.

Mineral Soils

Optimized for clay, silt, and sand mixtures withstandard mineral content.

±1% VWC

Organic Soils

Specialized calibration for high organic matter content and peat soils.

±1.5% VWC

Saline Soils

Advanced algorithms compensate for electrical conductivity variations.

±2% VWC

What TDT⁵ Does Differently

Patented innovations that set new standards for soil moisture measurement accuracy, durability, and cost-effectiveness.

5× Effective Antenna Length

Patented antenna design achieves 75cm effective length in a 15cm sensor body for comprehensive soil profile measurement.

Uniform accuracy across entire measurement depth

Integrated Electronics + Antenna

Single integrated design reduces manufacturing complexity and eliminates connection points that can fail.

Lower costs and maximum durability

400,000 Pulses Per Measurement

Massive oversampling with advanced digital filtering ensures consistent, repeatable results.

Uniform accuracy across entire measurement depth

Fully Enclosed Design

Antenna completely encapsulated in epoxy and polycarbonate with no exposed metal parts.

Lower costs and maximum durability

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FAQs

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How is TDT⁵ different from traditional soil moisture sensors?
TDT⁵ uses Time Domain Transmissometry with a five times longer effective antenna length and multi-depth measurement segments. This allows it to measure moisture across the full soil profile instead of at a single point. The result is higher accuracy, better stability, and a clearer understanding of how water moves through the soil.
Does TDT⁵ require calibration for different soil types?
TDT⁵ is designed to perform consistently across a wide range of soil types with minimal calibration. Unlike capacitance sensors, it does not require frequent soil-specific recalibration and maintains stable readings over long-term deployments, even in clay-rich or saline soils.
How deep can TDT⁵ measure soil moisture?
TDT⁵ itself is the measurement technology; the actual depth depends on the specific sensor:

‍GroPoint Profile (multi-depth probe using TDT⁵)Available lengths: 30, 45, 60, 75, 90, and 120 cm (up to 120 cm / 4 ft total depth).The probe is installed vertically and measures continuous soil moisture over the entire length , divided into 15 cm (6") segments .Each segment reports the average volumetric water content over its 15 cm zone.

‍GroPoint Lite (single-point sensor using TDT⁵)Measures over about 15 cm (6") of soil around the sensor.Installed vertically: averages moisture over a 15 cm layer.Installed horizontally: measures at a specific depth (where you place it).

So with TDT⁵-based GroPoint sensors, you can profile soil moisture from the surface down to 120 cm, with 15 cm resolution on the Profile probe, or monitor a single 15 cm layer with the Lite.
How does TDT⁵ perform in saline or clay-heavy soils?
TDT⁵ maintains accurate and repeatable measurements in saline and clay-rich soils where other technologies often fail. Its measurement approach is less sensitive to electrical conductivity, reducing signal distortion and long-term drift in challenging soil conditions.
Can TDT⁵ be integrated with existing data loggers or IoT systems?
Yes. TDT⁵ sensors are designed to integrate with a wide range of existing data loggers and IoT systems.

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Apply our technology to your soil moisture measurement applications.

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Precision soil moisture measurement technology. Patented TDT⁵ time-domain transmissometry delivering unmatched accuracy for agriculture and research.

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