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Enabling better global research outcomes in soil, plant & environmental monitoring.

Dynagage Logger

The Dynagage Logger from ICT International is a rugged, self-contained, standalone logger designed to collect data from any Dynagage Stem Gauges and Microsensors.

Designed to allow easy access to the collected data, the Dynagage Logger stores data on an internal MicroSD card for retrieval either using the USB port, 2.4GHz wireless network, or when combined with the ICT International Telemetry hub, via the mobile phone or Iridium satellite networks.
Within Combined Instrument Software (CIS) Dynagage Stem Gauges and Microsensors are pre-programmed in a look up database. The dedicated user interface in CIS allows the user to configure the Dynagage Logger with logging frequency and to view live measurements, download, and view files. Powered by a Lithium Polymer battery charged either via a solar panel for field applications, or the CH24 24 Volt power supply from ICT International for laboratory applications, the Dynagage Logger is a versatile logger for a variety of applications.

Dynagage Specifications:

Model No. Diameter Ht. (mm) Input Volts Typical Power (w) No TC Pairs TCGap dx (mm)
Min. (mm) Max (mm)
Microsensors
SGA2-WS 2.1 3.5 35 2.3 .05 1 0
SGA3-WS 2.7 4 35 2.3 .05 1 0
SGA5-WS 5 7 35 40 .08 2 3
Stem Gauges
SGB9-WS 8 12 70 4.0 .10 2 4
SGB10-WS 9 13 70 4.0 .10 2 4
SGB13-WS 12 16 70 4.0 .15 2 4
SGB16-WS 15 19 70 4.5 .20 2 5
SGB19-WS 18 23 130 4.5 .30 2 5
SGB25-WS 24 32 110 4.5 .50 2 7
Trunk Gauges
SGB35-WS 32 45 255 6.0 .90 4 10
SGB50-WS 45 65 305 6.0 1.4 8 10
SGA70-WS 65 90 410 6.0 1.6 8 13
SGA100-WS 100 125 460 8.5 4.0 8 15
SGA150-WS 150 165 900 9 13 8 20

 

Logger Construction: Extruded, hard anodised aluminium body.
UV, moisture, and impact resistance endcaps.
316 stainless steel external fasteners.
Sealed service hatch provides access to power switch, USB port and MicroSD card.
Power: Internal Lithium Polymer battery, rechargeable via 20w solar panel or 24 Volt power supply.
Data Storage and transfer: Format: CSV
MicroSD cards up to 32GB, SDHC, FAT32.
Logging Modes: 10 minute to 1 hour logging intervals.
Suspend Measurement mode.
Live view mode, allows the user to view measurement in real time.
User Configurable Parameters for Logging: Tissue Type.
Dynagage model.

The Dynagage Sap Flow Sensors are for measuring the sap flow, and thus the water consumption of plants. These energy balance sensors measure the amount of heat carried by the sap which is converted into Real-Time sap flow in grams or kilograms per hour. The sensors are non-intrusive and not harmful since the plants are heated up 1°C to 5°C typically.

The principles of heat balance sensors are scientifically proven and references exist for most major crops. Dynagages require no calibration since sap flux is directly determined by the energy balance and rates of heat convection by the sap flow.

The need for this technology is great because it is an affordable and practical way to measure the water use of herbaceous or soft stem plants of agricultural, economic and ecological importance. These plants are typically rice, wheat, lupin, chickpea and vegetables. Plants in greenhouses, nurseries or natural environments can be measured with the same ease.

Energy Balance Equations

Dynagage Diagram

The energy balance is:
Pin = Qr + Qv + Qf         (W)
Pin = V2/R (W) from Ohm’s law
(1)
Vertical conduction components are:
Qv = Qu + Qd
Qu = KST A dTd/dx
Qd = KST A dTd/dxKST = stem thermal conductivity (W/m x °K)
A = stem area (m2)
dTu/dx = temperature gradient (°C/m)
dx = thermocouple junction spacing (m)
(2)
Qr = Ksh x CH
Ksh = sheath conductance (W/mV)
Ksh is determined by solving equation (1) during zeroflow,
Qf = 0:
(3)
Ksh = (Pin – Qv) /CH (W/mV)
CH = radial-heat thermopile voltage (mV)
(4)
Finally:
F = (Pin – Qv – Qr)/Cp x dT (g/s)Cp = specific heat of water (J/g x °C)
dT = temperature increase of sap (°C)
dT = (AH = BH)/2 (°C)
(5)