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Review of the Leaf Sensor Bio-feedback System November 2, 2009

Posted by aeroponicsman in bio-feed back, Leaf Sensor, leaves, plants.
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AgriHouse updated its line of the SG-1000 Leaf Sensor Bio-feedback System. It now includes a stand-alone leaf sensor, micro-disk calibration standards set, analog to digital module, and software for analysis and control of irrigation systems.

LS and Meter

SG-1000 Leaf Sensor connected to a standard digital multimeter (shown w/ Calibration Std)

AgriHouse’s SG-1000 Leaf Sensor is available as stand-alone device.  It comes with its own calibration standard as well.  The SG-1000 Leaf Sensor can be connected to any common digital multimeter. The multimeter will give the user an instant reading of a plant’s moisture level. It works in real-time from the multimeter as power source with the read-out in volts (shown here). You will need a multimeter with NPN/PNP testing capability to utilize its 3 volt power source (or connect it to a battery).

AgriHouse also combined all of the components into a single product package which includes four leaf sensors. These same components were used by the USDA in a demonstration field study under AgriHouse’s National Science Foundation (NSF) grant.

AgriHouse’s SG-1000 Leaf Sensor Analysis and Control Software has four individual graphs for instant read-outs of a leaf’s moisture level. The moisture level is an indirect reading of the leaf turgidity (turgor pressure) or simply put – leaf thickness. The user can select when and how the moisture data is updated into the graphs. AgriHouse devised the software to provide the user with the option to read the leaf moisture in volts, micromenters and something it calls Seeligs.  The graphs automatically scroll based upon the user settable averaging period.


SG-1000 Leaf Sensor Analysis & Control Software simulation screen shots

The Leaf Sensor software interface uses the standard National Instruments (NI) Labview screens.  Fortunately the user doesn’t have to purchase NI’s expensive professional Labview software – instead AgriHouse packages all the drivers and executable Labview software on a DVD.  The software runs in WinXP and Window 2000.

Moisture data can be stored in a data file that the user creates. The data  can later viewed using Microsoft Excel. Data charts and graphs can be created right in Excel spreadsheets by the user. There is also a simulation mode available in the software.


SG-1000 Leaf Sensor DAQ Module

AgriHouse utilizes a DAQ ( data acquistion) OEM Module from NI. As with the a digital multimeter the user connects the ground, power and signal wires directly into the DAQ. The DAQ connects to a PC by means of a USB cable. The DAQ converts leaf sensor analog signal into a digital out. The device has four individual leaf sensor inputs, each capable of turning ON and OFF two separate digital output lines.  That’s eight individual digital output ports the user can use to attach their solenoids, switches and pumps to the module. The outputs have an enable/disable mode based upon upper and lower limits mode with settable hysteresis for each leaf sensor input.

Calibration Cards

SG-1000 Leaf Sensor Calibration Standards

AgriHouse also offers a calibration standard set. It comes on a single card with seven precision micro-thin disks for calibrating each leaf sensor.  The seven micro-thin disks each have a tolerance of + 0.00001 inches. These can used as calibration standards for thin and thick plant leaves.  The card contains areas for entering a leaf sensor number and the voltage for each micro thin disk.

The user can choose to purchase AgriHouse’s stand-alone SG-1000 Leaf Sensor with a digital multimeter (and upgrade after some hands-on experience with measuring a plant’s leaf moisture level) or purchase the entire leaf sensor software package for immediate precision irrigation control.

For the complete line of SG-1000 Leaf Sensor Bio-feedback components and hardware visit  www.leafsensor.com