A Microprocessor Based Soil Moisture Sensor System for Space Based Plant Growth Units Orbital Technologies Corporation

Format:

Conference/Event

Author/Creator:

Morrow, Robert C., author.

Conference Name:

31st International Conference On Environmental Systems (2001-07-09 : Orlando, Florida, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2001

Summary:

A soil moisture sensor system consisting of small heat-pulse probes, a microcontroller, and software for data acquisition and signal conditioning was developed for use in space based plant growth units. The microcontroller allows the sensors to be used in a control application with minimum time demands on the control subsystem. A single digital serial link may be shared by up to 16 microcontrollers with 8 sensors each, for a total of 128 sensors. The microcontroller independently applies heat cycles to determine the current moisture level, and responds to a request from the computer with the last known value. Using the microcontroller system, repeatability testing was completed for wet 12 mm arcillite. The standard deviation in wet arcillite over a 16-hour period was about 3%. Software filtering can be used to reduce the standard deviation further. In addition to determining root zone moisture levels, this system can also be used to monitor root zone temperature and to detect wavefront movement through a dry rooting medium

Notes:

Vendor supplied data

Publisher Number:

2001-01-2178

Access Restriction:

Restricted for use by site license