Overview

• The most cost-effective, accurate, and reliable sap flow sensor available for scientific research.
• Simultaneously measures 30+ physiological parameters—including sap flow, sap flux density, stem water content, thermal properties, stem temperature, and more.
• Seamless digital integration with a wide range of data loggers and IoT devices, supporting the SDI-12 protocol.

The Implexx Sap Flow Sensor is revolutionizing the work of physiologists, hydrologists, consultants, engineers, and students alike. Its unique combination of scalability, precision, and versatility makes it an essential tool for researchers worldwide. Here’s why:

• Expanded sample size and replication.
• Unmatched accuracy and reliability.
• Simplicity with flexible complexity.

Thanks to these features, the Implexx Sap Flow Sensor is already driving breakthroughs in research at top-tier institutions, including NASA and the USDA in the USA, the Chinese Academy of Sciences, the University of Tokyo, CREAF, the University of Helsinki, CSIRO, Plant & Food Research, and many more. The Implexx Sap Flow Sensor is enhancing research outcomes globally.

Expanded Sample Size and Replication
In any study, a larger sample size leads to more robust conclusions. A sample size of 30, for instance, offers far greater statistical power than a sample size of three. This is a fundamental principle of research. The Implexx Sap Flow Sensor allows researchers to significantly scale up their sample size, offering unparalleled cost-effectiveness.

This isn’t just a marginal improvement—depending on experimental design, the Implexx Sap Flow Sensor can reduce costs by 50-90% compared to comparable sensors. But it’s not just about the number of sensors; it’s about depth. While many traditional sensors (like Granier’s thermal dissipation probes) provide only a single data point within the tree, the Implexx sensor measures 2-5 points to a depth of 60 mm. This multi-depth capability gives researchers a far more comprehensive understanding of total sap flow, resulting in richer data and higher-quality publications.

Unmatched Accuracy and Reliability

At its core, a sap flow sensor must do one thing exceptionally well: measure sap flow. However, most sensors only capture a limited range of sap flow velocities—some are better for low flows, others for high. The Implexx Sap Flow Sensor stands apart as the only commercially available heat pulse sensor that measures the full spectrum of sap flow: from reverse (negative) flow, to zero, slow, fast, and even extremely fast flow.

This unparalleled accuracy allows researchers to capture a complete picture of sap dynamics within plants. Engineered for durability, the Implexx Sap Flow Sensor incorporates advanced, miniaturized electronics housed in low thermal conductivity materials, with an IP68 rating for environmental resilience. Designed to last, it ensures reliability even in long-term field studies. For example, a single sensor in a pear tree near Melbourne, Australia, has been consistently recording data for over five years.

Simplicity with Flexible Complexity

Some researchers seek straightforward sap flow measurements they can trust, while others prefer to explore the deeper complexities of sap flow dynamics. The Implexx Sap Flow Sensor is designed to cater to both needs. It can be deployed quickly for simple, reliable data or configured for more advanced, in-depth studies.

What sets the Implexx sensor apart is its ability to go beyond standard sap flow measurements. In a single deployment, it captures 30+ physiological parameters—including sap flow, sap flux density, thermal properties, stem temperature, stem water content, and more. This comprehensive data range provides researchers with an unparalleled level of insight in one compact device.

Furthermore, the sensor is highly adaptable. As a digital sensor, it easily integrates with any data logger or IoT device supporting the SDI-12 protocol. For those seeking a more streamlined solution, Implexx and its partners offer a ready-to-go, plug-and-play setup, delivering pre-programmed, internet-enabled data loggers that are wired, assembled, and ready for immediate use.

Versatile Data Logging Solutions

The Implexx Sap Flow Sensor is supported by the SDI-12 protocol which gives it tremendous flexibility to connect to many data logging devices.

Implexx is supported by a world-wide team of dealers who can provide a comprehensive range of data logging solutions. This includes the complete range of Campbell Scientific data loggers and many more brands.

Alternatively, the Implexx Sap Flow Sensor can be integrated into your existing data logging infrastructure. Implexx provides a comprehensive range of guides and manuals to assist you, or you can contact us for further assistance.

Low Power, Less Management

The Implexx Sap Flow Sensor is a heat pulse style sap flow sensor therefore it requires relatively low power. The Implexx engineers have added features to the Implexx Sap Flow Sensor to further improve the power efficiency of our sap flow sensor. The Implexx Sap Flow Sensor is therefore an ideal sensor for measuring sap flow in forests and remote field sites.

In our experience, we’ve installed the Implexx Sap Flow Sensor at field sites with the following power requirements:

• A 20W solar panel, with a 12V 9 amp hour battery, supporting 12 x Implexx Sap Flow Sensors plus a modem, 12 x dendrometers, soil moisture and air temperature sensors;
• A 5W solar panel, with a 12V 7 amp hour battery, supporting 2 x Implexx Sap Flow Sensors;
• A stand-alone 12V, 9 amp hour battery, with a 30-minute logging interval, supporting 1 x Implexx Sap Flow Sensor for 30 days.

Measure Fast, Slow and Reverse Sap Flow

The Implexx Sap Flow Sensor is the only commercially available heat pulse sensor that can measure the entire observable range of heat velocity and sap flow in plants.

The Implexx Sap Flow Sensor sensor utilizes the Dual Method Approach (DMA) heat pulse method which has a measurement range is between -200 to >1000 cm/hr (heat velocity) or -100 to >2000 cm³/cm²/hr (sap flux density).

The Implexx Sap Flow Sensor wide measurement range compares with the narrow range of the heat ratio method (HRM; -10 to +15 cm/hr), or the inability of the compensation heat pulse method (+5 to >1000 cm/hr) and Tmax (+10 to >1000 cm/hr) to measure at slow velocities (Forster, 2019). The inability of the other heat pulse methods to measure the entire range of sap flow in plants means they are unreliable, inaccurate and can lead to misinterpretation of data. The Implexx Sap Flow Sensor is the only reliable sensor that can measure the entire range of sap flow in plants.

A Calibrated Sap Flow Sensor

Recent reviews of sap flow methods have strongly recommended that sap flow sensors are calibrated for the trees they are measuring (Steppe et al., 2010; Forster, 2017; Flo et al., 2019). Without a species-specific, or site-specific, calibration, the average error in sap flow estimation is 35% (Forster, 2017).

The Implexx Sap Flow Sensor is the only sap flow sensor available that has a built-in calibration. The Implexx Sap Flow Sensor calibration has been supported by scientific studies demonstrating its accuracy across taxonomically diverse range of 15 woody species. The main output from the Implexx Sap Flow Sensor is calibrated sap flow.

But, as any good scientists knows, you should always check a sensor’s calibration against your own standard. Therefore, we provided all the raw data required to check measurements and to perform your own calculations.

Multiple Measurement Points

The Implexx Sap Flow Sensor is configured to measure two to five sapwood radial depths. The IX-SF30 model has 30 mm length needles with two measurement depths. The IX-SF60 model has 60 mm length needles with five measurement depths. Multiple measurement points in the sapwood are advantageous because:

• increases the accuracy of the Implexx Sap Flow Sensor over older technology such as the thermal dissipation or Granier probe;
• the outer and inner sapwood provide insights into plant physiological processes; and
• the ratio of outer to inner sap flow has been used as a measure of water stress.

Hydraulic Redistribution and Reverse Flow

The Implexx Sap Flow Sensor is a three-probe configuration with a downstream and upstream temperature needle to a central heater needle. The three-probe configuration means that sap flow can be measured in the positive (i.e. from the roots to the canopy) and reverse (i.e. from the canopy to the roots) direction. This feature cannot be found in single probe or two-needle designs. Therefore, any research on hydraulic redistribution must consider the the Implexx Sap Flow Sensor.

It is also possible to install the Implexx Sap Flow Sensor on the roots. Various configurations of the cable length can be designed to assist and accommodate, as best as possible, these types of research projects. Contact the team at Implexx for more information.

Canopy Stomatal Conductance

The Implexx Sap Flow Sensor, combined with an ATMOS 41 Weather Station, can also be used to measure canopy conductance (also referred to as canopy stomatal conductance).

The Implexx Sap Flow Sensor is installed on the trunk or stem of the plant or tree. Typically, the sensor is installed lower on the trunk beneath the crown. However, some experiments or hypotheses may test canopy conductance at various locations along the trunk such as upper versus lower branches or northern versus southern aspects.

The ATMOS 41 Weather Station is needed to measure atmospheric evaporative demand variables including vapour pressure deficit (VPD), wind, solar radiation, temperature, and relative humidity.

The weather station should be installed as close as possible to the measured plants while still following standard protocols on where to install a weather station (i.e. in the open and away from obstructions).

Implexx Sap Flow Sensor Features

• Easy to install and requires little ongoing maintenance;
• An option between 30 mm or 60 mm length sensors with up to 5 measurement depths;
• Outputs a comprehensive range of 33 parameters per measurement;
• Or simplifies it down to a single output of calibrated sap flow;
• Output raw temperature data for your own models and equations;
• SDI-12 protocol so it can be supported by a large range of data loggers.

Specifications