Abstract: A system and method for providing cooperative control of irrigation between a groundskeeper having immediate supervision on plants to be irrigated and management personnel remotely located by using weather data and water budget restrictions. The system implements a method that involves responding to a signal from an atmometer that a predetermined "threshold" amount of water has been lost to evapotranspiration at or near an irrigation station. A daily total of these threshold signals are stored in a weather table for use in automatically determining a quantity of water that has been lost to evapotranspiration at the station since the most recent irrigation. The determined quantity is automatically combined with an evapotranspiration factor in order to determine how much water to replace. Alternatively, current data received from a remote site may used by the machine executed means to override the weather data table.

Abstract: A probe for sensing the moisture content in a porous medium such as soil. The probe includes an array of a multiplicity of conductors and resistors formed on a substrate, with contact pins or electrodes connected to one end of each resistor, typically extending outwardly from the substrate. The resistor array is preferably divided into at least two groups, providing a separate output for each group. An appropriate voltage source and indicator means are connected to the resistor array in a circuit to provide indication of soil moisture. The transfer characteristic of the apparatus is such that the probe has improved sensitivity in the area of primary interest, that is at, between 80 and 100% of saturation.

Abstract: A parallel analog-to-digital converter having high speed and high resolution, fabricated on a single integrated-circuit chip in such a manner as to avoid problems typically associated with high speed parallel converters. The converter disclosed by way of example has an eight-bit output, 256 matched comparators for quantizing an analog input signal, and encoding and latching logic for deriving digital outputs from the comparators. Problems related to comparator mismatching, high comparator input capacitance and high comparator input bias current, are effectively minimized by the use of a triple diffusion fabrication process, which substantially reduces the number of defects in the circuit and provides a relatively high component packing density.