Dynagage PDF Brochure

Dynagage™ Sap Flow SensorsDynagage SummaryThe Dynagage Sap Flow Sensors are the latest technology 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 1ºC to 5ºC typically. The principles of heat balance sensors are scientifically proven and references exist for most major crops and many tree species. Unlike other methods, 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 new technology is great because it is an affordable and practical way to measure the water use by plants of agricultural, economic and ecological importance. Plants in greenhouses, nurseries or in natural environments can be measured with the same ease.Dynamax introduced the first sap flow sensor prototypes in 1988 and today offers a full range of sensors from 2 mm up to 150 mm.Microsensors 2 to 5 mmThe Dynagage Microsensors measure transpiration by small diameter crops, cereals, seedlings or floricultural species. Petiole and peduncle sap flow measurements are now possible.Features• Durable acrylic shell, patented hinged clam-shell design• Flexible inner core conforms to stem shape• Very low power 0.07 WStem Gages 9 to 32 mmFeatures• Direct transpiration measurement• Strap-on sensor collar• Non-invasive and flexible• Constant heat-energy balance• Real-time monitoring and recording• 1 year warrantyBenefits• Absolute measurement and no calibration required• Reusable and portable• Harmless and conforms to plant size• Reliable and proven method• Measures absolute mass-flow• Helps correct decision makingTrunk gages and stem flow gages.SGB16 sap flow sensor with weather shield attached.Microsensors (left to right) SGA5, SGA3, SGA2.Dynagage™ SpecificationsEnergy Balance EquationsThe energy balance is:Pin = Qr + Qv + Qf (W) (1)Pin = V2 /R (W) from Ohm’s lawVertical conduction components are: Qv = Qu + Qd (2) Qu = KST A dTd/dx Qd = KST A dTd/dx Kst = stem thermal conductivity (W/m x oK)A = stem area (m2)dTu/dx = temperature gradient (oC/m)dx = thermocouple junction spacing (m)Qr = Ksh x CH (3)Ksh = sheath conductance (W/mV)Ksh is determined by solving equation (1) during zero-flow, Qf = 0:Ksh = (Pin - Qv) /CH (W/mV) (4)CH = radial-heat thermopile voltage (mV)Finally:F = (Pin - Qv - Qr)/Cp x dT (g/s) (5)Cp = spec ific heat of water (J/g x oC)dT = temperature increase of sap (oC)dT = (AH = BH) /2 (oC)Tree-trunk gages applied to rain forest research inside the Biosphere II dome in Oracle, Arizona. Picture by permission of Biosphere II.Trunk Gages 32 to 125 mmTrunk gages are unique tools for the measurement of sap flow in trees. A myriad of applications are solved by knowing tree water usage. Trunk flow gages have advanced designs that combine all temperature signals into three signal outputs and a heater voltage sensing output compatible with all other Dynagage signal connections.Trunk gages have four or eight pairs of differential temperature sensors spaced around the circumference of the trunk, as shown in the chart below. This advanced design ensures that flow rates that vary around the circumference are accurately monitored and averaged into one reading. Up to 18 radial heat flux sensing thermocouples are also spaced evenly around the circumference to ensure that radial heat is accurately monitored.With the capability to monitor sap flow in tree branches, important canopy studies can be performed. Water conductivity and tree transpiration may be partitioned into the flow rates related to the canopy level.Dynagage SummaryMicrosensorsSGA2-WS 2.1 3.5 35 2.3 .05 1 0SGA3-WS 2.7 4 35 2.3 .05 1 0SGA5-WS 5 7 35 4.0 .08 2 3Stem gagesSGB9-WS 8 12 70 4.0 .10 2 4SGA10-WS 9 13 70 4.0 .10 2 4SGA13-WS 12 16 70 4.0 .15 2 4SGB16-WS 15 19 70 4.5 .20 2 5SGB19-WS 18 23 130 4.5 .30 2 5SGB25-WS 24 32 110 4.5 .50 2 7Trunk gagesSGB35-WS 32 45 255 6.0 .90 4 10SGB50-WS 45 65 305 6.0 1.4 8 10 SGA70-WS 65 90 410 6.0 1.6 8 13SGA100-WS 100 125 460 8.5 4.0 8 15SGA150-WS 150 165 900 9 13 8 20Dynagage ApplicationsAgricultural Engineer HydrologyAgricultural Consultant Irrigation SystemsBotanist Orchard MonitorCitrus Grower OrnamentalsCrop Science Plant PhysiologistCrop Physiology PhytoremediationEntemology Pollution StudiesExtension Service PomologyFarm Industry Reforestation Fertilizer Evaluation River Water AuthorityGenetic Engineering Seed GeneticsGlobal Climate Change Tree FarmGreenhouse Control Weed ScienceForestry Planning Water ConservationHorticulture Xeriscape Plant SelectionDynagage sensors work well with most of the worlds major crops and trees. Vines, shrubs, natural vegetation, and ornamentals can also be monitored with the Dynagage Sap Flow System.Species Monitored by DynagageCrops Tree OtherCucumber Almond CoffeeCotton Apple GrapeCorn Avocado KiwiSorghum Bald Cypress LigustrumSoybean Douglas Fir MesquiteSugarcane Eucalyptus PotatoSunflower Ficus RoseSweet Potato Kumquat Tomato MangosteenWheat Oak Orange Pecan Pine - Xmas Tree Pine - Lobolly Poplar Red Cedar TangerineSGA5 microsensor, with weather shield, monitors okra plant transpiration.Comparing peach tree hourly transpiration to evapotranspiration demand computed from Penman-Van Bavel modeling software and Dynamet Weather Station.Peach and pecan tree accumulated daily water consumption declines 25 and 20% under limited water availability as ETP demand increases.Dynagage™ ApplicationsDynamax Inc10808 Fallstone Rd #350Houston, TX 77099 USATel: 281-564-5100 Fax: 281-564-5200admin@dynamax.comwww.dynamax.com