multi-sensor sap flow system

  • Multi Sensor Sap Flow SystemA low cost, all-in-one, system to measure multiple sap flow sensors and critical environmental variables including vapour pressure deficit, solar radiation, soil moisture and soil CO2 concentration
  • Measure high rates (up to 200 cm / hr), low rates and reverse rates of sap flow with a heat pulse velocity sensor
  • The system is pre-programmed, pre-packaged and ready to be installed at your field site
  • Free Excel-based software to convert heat velocity to sap velocity and sap flow
  • Optional remote download over the internet, with remote access to data logger to change parameters, available


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sap flow sensors

The Multi-Sensor Sap Flow System supports the heat pulse velocity sensors manufactured by East 30 Sensors. Up to 10 x SF3C Sap Flow Sensors can potentially be installed on a single data logger as part of the Multi-Sensor Sap Flow System.

East 30 Sensors manufactures a range of sap flow sensors based on the heat pulse measurement principle.

Choose between the default sensors, with three needle configuration, or we can customise sensors, including cable length, for your specific project.

The East 30 Sensors HPV sap flow sensors have 4 main advantages over other sap flow sensors:

  • Low cost per sensor means you can increase sample size, replicates and produce better scientific and monitoring outcomes
  • Exceptional performance and accuracy under high flow conditions
  • 3 temperature measurement points across the radial profile for accurate estimation of whole tree water use
  • Reliability and robustness – the East 30 Sensors sap flow sensors have been manufactured since the early 1990’s and are designed to last in the field for years at a time

The East 30 Sensors HPV sap flow sensors are based on scientific research published by Marshall (1958) and Cohen et al (1981). An 3 second heat pulse is applied to one of the needles and sap movement carries this pulse downstream towards the temperature needles. The time taken for the peak of the heat pulse to reach the temperature sensors is noted. Theory states that this time is directly related to the sap flow velocity. The velocity is used, along with the sapwood area and size of the tree, to calculate total tree water use and transpiration.

The East 30 Sensors HPV sap flow sensors are unique in having 3 temperature measurement points along the radial profile. The temperature sensors are located at 5mm, 17.5mm and 30mm along the 35mm length of the needles.

By measuring at 3 points along the radial profile, the outer, middle and inner portions of the sapwood can be characterised in detail. This leads to a more accurate estimation of total tree water use.


meteorological sensors

Edaphic Scientific can configure your Multi-Sensor Sap Flow System to have a range of meteorological variables that are critical for understanding sap flow dynamics.

Parameters include:

  • Solar radiation
  • Temperature
  • Relative humidity
  • Vapour pressure deficit (VPD)
  • Penman-Monteith evapotranspiration
  • Sonic wind speed & direction
  • Rainfall

The sensors can be installed close to the plant’s canopy to characterise the environment the plant is experiencing and the energy that is driving sap flow. Alternatively, the sensors can be installed according to World Meteorological Organisation guidelines for traditional meteorological data collection.

More information on our range of meteorological sensors.


soil moisture and CO2 sensors

Soil Moisture and Temperature ProbeEdaphic Scientific can configure your Multi-Sensor Sap Flow System to measure soil moisture at one or more depths in the soil profile.

The Multi-Sensor Sap Flow System can also monitor soil CO2 concentration, carbon dynamics and respiration with the Eosense CO2 sensors.

Single sensor or profile probes can be installed to measure the following parameters:

Parameters include:

  • Volumetric soil water content
  • Soil temperature
  • Soil electrical conductivity / salinity
  • Soil CO2 concentration

More information on our range of soil moisture sensors.


data logger & remote access

The Multi-Sensor Sap Flow System is built around Campbell Scientific’s CR1000 data logger. The CR1000 is a versatile, advanced data logger that can support up to 48 x analog channels (with a multiplexer), numerous pulse channel and digital channels.

Edaphic Scientific can configure and program the CR1000 for your specific requirements. The CR1000 is delivered in an environmentally weather proof, lockable enclosure with optional solar panel power supply.

Data can be downloaded directly from the CR1000 with a USB cable. Alternatively, Edaphic Scientific can provide remote, telemetry access to your data logger. Data can be accessed from anywhere in the world with an internet connection. SMS and email alarms and alerts can also be configured with the CR1000 data logger.

More information on our range of data loggers.