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Agricultural Electronics Corporation makes two types of automatic dendrometers for the measurement of growth and reaction of a plant or tree to environmental changes.
Automatic Point Dendrometers - measures changes in the radius of a branch or main stem with a rod held against the outside surface by a constant force.
Automatic Band Dendrometers - measures changes in circumference with a band wrapped around the branch or main stem and held by a constant force.
Shown below is a schematic of the Automatic Point Dendrometer
The general characteristics of the automatic recording dendrometers are shown in the table below.
In addition to the automatic recording dendrometers we also produce a highly sensitive yet inexpensive Manual Band Dendrometer. A description and technical specifications are shown in a separate table.
See the Dendrometer User Group pages for the exchanges of experiences with AEC dendrometers.
|Element||Automatic Point Dendrometers||Automatic Band Dendrometers|
|Resolution||Two micrometers change in radius||Two micrometers change in circumference.|
|Size and Weight||Approximate size: 20 cm by 10 cm by 18 cm; Weight: 310 grams||Approximate size: 11 cm by 15 cm by 6 cm; Weight: 365 grams|
|Methodology||Sensing rod is held against outside surface of branch or main stem by a constant sensing force. As radius changes the position of sensing rod changes||Band is wrapped around and held against the perimeter by a constant band tension. Change in circumference changes the length of the band relative to a fixed point.|
|Band Tension Principle||Constant Force Spring|
|Sensing Rod Force Principle||Constant Force Spring|
|Sensing Force and Tension Characteristics||Rod Force 0.3 newtons; Rod Pressure: 0.38 newtons per square inch||0.54 newtons (Band Tension)|
|Readings||Changes can be read automatically using a linear variable differential transformer (LVDT) for conversion from displacement to electrical voltage. See POD Package||Changes can be read automatically using a linear variable differential transformer (LVDT) for conversion from displacement to electrical voltage. See POD Package|
|Unadjusted Range||15,000 micrometers||15,000 micrometers|
|Band Material Supplied||Material: Hastalloy 276 or Invar 36 as specified by the user.* Three meters length. Width: 3 mm. Thickness 75 microns.|
|Temperature Sensitivity||Determined by length and composition of band material. Coefficient of thermal expansion: Hastalloy 276: 11.2 micrometers/meter/degree C; Invar 36*: 1 micrometers/meter/degree C.|
|Adjusted Range||50,000 micrometers without mounting adjustment||Depends on the amount of spare band material at the time of installation|
|Assembly Materials||Brass, stainless steel, G10||Brass, stainless steel, nylon, G10|
|Mounting Assembly||Three 4 mm outer diameter threaded rods (#8-32) each 17.8 cm long||Two 4 mm outer diameter threaded rods (#8-32) each 17.8 cm long|
|*Footnote||Invar 36 can be supplied if specifically requested. However, it will corrode rapidly and will stain bark. The toxicity of this staining is presently unresolved.|
|PHYTOGRAM - Applications and specifications||Automatic Point and Band Dendrometers - For precise measurements of growth|
|POD - In-the-field solar powered data collection computer operating over extended period of time in various environmental conditions||Manual Band Dendrometers - Schematic drawing and product characteristics|
|Equipment Cost and Support Services - Products, Services, and typical Research Packages||Automatic Root Dendrometers - For measurement of diurnal cycles and growth rates of roots near the surface.|
|Ontogenetic Irrigation Scheduling- When to water and how much to water based on plant development over four seasons||Dendrometer User Group Pages|
|Data Transfer Methods - Various alternatives- primarily cell phone and radio communication capabilities|
|Water Content Levels of Wine Berries- for wine industry, using the Phytogram for indicator of hydration status and berry ripeness|
|Environmental Sensors - For concurrent assays of air and ground temperature, light, and soil moisture||Communicating with Agricultural Electronics Corporation - By E-mail, US Postal Service, Telephone and Fax|
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