single sensor sap flow system
- A low cost, all-in-one, system to measure sap flow and critical environmental variables including vapour pressure deficit, solar radiation and soil moisture
- 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
- Heat pulse velocity sap flow sensors
- Weather sensors
- Soil moisture sensors
- Soil CO2 concentration
- Leaf temperature
- Plant water potential
The Single Sensor Sap Flow System supports the heat pulse velocity sensors manufactured by East 30 Sensors.
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.
- Solar radiation
- Relative humidity
- Vapour pressure deficit (VPD)
- Sonic wind speed & direction
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.
soil moisture sensors*
Edaphic Scientific can configure your Single Sensor Sap Flow System to measure soil moisture at one or more depths in the soil profile. Single sensor or profile probes can be installed to measure the following parameters:
- Volumetric soil water content
- Soil temperature
- Soil electrical conductivity / salinity
data logger & remote access
The Single Sensor Sap Flow System is built around Campbell Scientific’s CR300 data logger. The CR300 is a low cost, basic data logger that can support up to 6 x analog channels, 1 x pulse channel and 20 x digital channels.
Edaphic Scientific can configure and program the CR300 for your specific requirements. The CR300 is delivered in an environmentally weather proof, lockable enclosure with optional solar panel power supply.
Data can be downloaded directly from the CR300 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 CR300 data logger.
*Disclaimer: depending on your system configuration, the Single Sensor Sap Flow System may only be able to configure a limited number of concurrent meteorological and soil moisture sensors. The system cannot support an unlimited number of sensors. For larger systems, see the Multi-Sensor Sap Flow System or contact Edaphic Scientific to discuss your requirements and research priorities.