The SFM1 Sap Flow Meter is a self contained, stand-alone instrument for the measurement of sap flow or transpiration in plants. The SFM1 is a complete package containing sap flow sensors, data logger, interface software and internal battery which can be charged with an external solar panel. The SFM1 Sap Flow Meter is a new model which replaces the HRM30 sap flow measurement sensor.
Utilising the Heat Ratio Method (HRM) principle the SFM1 Sap Flow Meter is able to measure high, low and reverse flow rates in both small woody stems & roots as well as large trees. Like the Heat Field Deformation (HFD) principle, the HRM Sap Flow Meter is the only instrument that can measure zero flow and reverse sap flow rates. The SFM1 Sap Flow Meter is the most powerful and flexible instrument for the direct measurement of plant water use.
Low & Zero Sap Flow Rates
Reverse Sap Flow Rates
Night Time Water Loss
Sap Flow in Roots
Arid Ecosystems & Drought
Radial Sap Velocity Profiles
Sap Flow of Grapevines
– SFT1 – Sap Flow Tool Software
– MCC1 – Wireless USB Radio communication device
– MCC2G – Remote Data Access Hub for Data To Web access via GSM
– SFM-SK1 – SFM Installation Kit
– SFM-55 – Pack of 10 Drill Bits
– SFM-TB – HRM block, Functional verification standard
– SP22 – 20 Watt Solar Panel and SPPM – Solar Panel Post Mount
Raw Temperatures: °C
Heat Pulse Velocity: cm hr -1
Sap Flow: cm 3 hr -1 (Litres hr -1 )
Range -100 to +100 cm hr -1
Resolution 0.01 cm hr -1
Accuracy 0.5 cm hr -1
Measurement Duration 120 seconds
User Adjustable: 20 Joules (default) approx. Equivalent
to a 2.5 second heat pulse duration, auto scaling.
User Adjustable: Minimum interval, 3 minutes,
recommended minimum 10 minutes.
Computer Interface USB, Wireless RF 2.4 GHz
Data Storage MicroSD Card
Memory Capacity Up to 16GB, 4GB MicroSD card included.
Needle Diameter 1.3 mm
Needle Length 35 mm
Measurement Positions 2 per measurement needle
Measurement Spacings 7.5 mm and 22.5 mm from the needle tip
Dimensions L x W X D 170 x 80 x 35 mm
Weight 400 g
Internal Battery Specifications
960mAh Lithium Polymer, 4.20 Volts fully charged
External Power Requirements
8-30 Volts DC, non-polarised, current draw is 190mA
maximum at 17 volts per logger
USB Power 5 Volts DC
Internal Charge Rate
60mA – 200mA Variable internal charge rate, maximum
charge rate of 200mA active when the external voltage
rises above 16 Volts DC
USB Power 100mA fixed charge rate
Internal Power Management
Fully Charged Battery 4.20 Volts
Low Power Mode 3.60 Volts – Instrument ceases to take measurements
2.90 Volts – Instrument automatically switches off at and
below this voltage when no external power connected.
Battery Life varies
• With a recommended power source connected, operation can be continuous.
• Approximately 1.5 days with a heat pulse of 50 Joules and a measurement
interval of 30 minutes – no external power present to recharge battery.