Automatic Dendrometers
Agricultural Electronics Corporation Home Page
Description.
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. |
| Welcome Page | |
| 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 |
| End of Page |