POD
Agricultural Electronics Corporation Home Page
The term "POD" designates the electronics and the housing for the electronics as a single unit. The POD package consists of the electronics and housing; cables for communication and solar collection; a solar collector; a mounting plate with mounting hardware; software installation and operating manuals. Within the POD enclosure is a cell phone or radio for data collection communication. The POD can be operated in virtually any climate over the four seasons.
The components of the typical production installation consist of:
(1) POD - enclosure with data recording electronics capable of monitoring thirty two sensor channels, a solar panel for electrical power generation, and connections to a cell phone or radio for communications. One channel is used for the drip line sensor and one channel for other purposes. The POD can monitor sensors from two fifteen sensor wiring harnesses. This permits simultaneous monitoring of petiole and fruit in fifteen plants or any combination of thirty sensors in various locations within the plant or plants.
(2) Wiring Harness - a woven plastic sleeve about 3/8 inch (8 mm) in diameter containing 15 individual sensor wires about 100 feet in length. Emerging from the sleeve every seven feet (2.1 meters) is a short length of wire about one inch (2.54 cm) long - seven in one direction and eight in the other direction from the POD. The harness is installed along the drip line in drip irrigated plants and connected to the POD. In production applications this accommodates the connection of extension wires from 15 petioles in one single row. This arrangement lends itself to permanent installation and can remain on the drip line during machine harvesting. When both petioles and berries are being monitored two harnesses are installed at the site.
(3) Extension Wires - about 75 inches (190 cm) long to connect the wiring harness to the 15 individual petioles (and 15 berries). Just before harvest, the extension wires (with sensors) are removed from the petioles and berries but the wiring harness and drip line sensor can remain.
(4) Sensors -- at the end of the extension wire is the noble metal sensor implanted inside the petioles (and berries) to record hydration status and other measurements. These sensors must be replaced each season.
Installation
The monitoring and communication equipment is installed in the field by Agricultural Electronics Corporation staff (or user trained staff if desired) at the location (or locations) selected by the user. The type of communications (radio and/or cell phone) is determined by field topography, cell phone signal strength, and number of sites being monitored. The installation of the wiring harness, drip line sensor, and petiole sensors is usually done in mid-June, with insertion of sensors into the berries when seasonally appropriate. The user is responsible for removal of the extension wires and sensors from the petioles and berries just prior to harvest (a 15 to 30 minute task).
Research Applications - Customized Installations
Sensor layout for research applications is highly customized to the particular objectives of the research. There are some broad guidelines to determine sensor compliment. In general, sensors wires move away from the POD as spokes in the wheel move away from the central hub. The POD has thirty-two sensor channels available. (Each automatic dendrometer requires two channels, all other sensors require one channel.) The standard distance from the POD to the sensor is forty meters. Greater distance is possible in individual circumstances. It is advisable to minimize the distance between POD and sensor consistent with research objectives.
Sensor wires can be run individually. Insulation on individual wires is moisture insensitive tefzel but it is better to keep the sensor wires out of standing water. Sets of four sensors going to a particular location will be run in a sleeved cable. This is advantageous if animal interactions or heavy human traffic are anticipated. Shallow burial of the sensor wires is possible. The soil sensors are fabricated for extended duration deep burial.
Detailed specifications are shown below.
| Element | Description |
| Sensor Capacity of POD | Thirty two channels. PHYTOGRAM™ and Environmental Sensors require one channel per sensor. Automatic Dendrometers require 2 channels per sensor. |
| Data Acquisition Rates | Data acquisition sampling rates can be set every 1, 2, 5, 10, 15, 20, 30, 60, 240, 720 and 1,440 minutes. Each sensor type can be sampled at its own rate. For production applications, data collection from petioles and berries is usually every 30 minutes, 24 hours per day. Resulting data can be displayed in 48 point detail or single minimum daily value. |
| Temperature Range | -50C to +50C |
| Standard Operational Range | Monitored plants must be within 40 meters of the POD in any direction. Further distances are possible at additional cost. |
| Memory Storage | The POD contains a two megabyte removable non volatile flash memory card. Acquisition of data from fifteen PHYTOGRAM™ hydration sensors at a rate of once per half hour for twenty-four hours requires 3,500 bytes of memory storage. |
| Environmental Operations | The POD will be mounted above ground and is equipped to pass air from inside to outside but not moisture. |
| Physical Dimensions | The fiberglass POD is 10" x 8" x 6" (25.4cm x 20.3cm x 12.7cm). It is mounted on a polypropylene plastic plate 8" x 22.7" x 0.375" (20.3cm x 57.1cm x 0.94cm). All mounting hardware is size #10 stainless steel. The POD is built to be mounted above ground. |
| Solar Power | One solar cell, 4.5 by 6.25 inches (11.4cm by 15.9cm) usually mounted directly above the POD. It can be mounted 25 meters from the POD if necessary. A shorter distance is desirable. In low sunlight locations, the size of the solar cell can be increased and connected to the POD via an extended cable. |
| Battery Life | With no solar charging the POD is capable of operating for one month; with solar charging battery life is unlimited |
| Data Transfer Hardware | Remote transfer is by cellular phone or radio. On-site transfer is via RS232 link to a laptop computer. The cable is part of the package. See Data Transfer Methods for separate description of alternatives. |
| On Site Data Transfer Software | PROCOMM (not provided in package) or HYPERTERMINAL (part of Windows 95,98, or NT) or equivalent programs. |
| Data Conversion Software | DOS based program to convert sensor data to text files. EXCEL macros to process data into graphical or tabular form. |
| Sensor Types | Potential, Current, Capacitance, Resistance, and Dendrometer. |
| Sensor Connectors | The POD has two DB25 male connectors for connection to the wiring harnesses. Additional connections are made for ground wires, communication, and solar collector cable. |
| 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 Production and Research Packages | Automatic Root Dendrometers - For measurement of diurnal cycles and growth rates of roots near the surface. |
| Irrigation Management- Optimize irrigation scheduling with PHYTOGRAM™ technology for water and pumping cost savings | Dendrometer User Group Pages |
| Data Transfer Methods - Various alternatives- primarily cell phone and radio communication capabilities | |
| Water Content Levels of Specific Crops- for wine industry, using the Phytogram™ for indicator of petiole 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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