Abstract: An irrigation controller includes a base unit with a removable and programmable control panel and backplane circuitry for communicating with a plurality of removable modules capable of performing a variety of irrigation and non-irrigation functions. A base module having irrigation station drivers is mated with the backplane circuitry and communicates with the base unit to carry out basic irrigation functions. A plurality of expansion modules and one or more smart modules, each having its own logic circuit, can be mated with the backplane circuitry to communicate with the base unit and carry out additional irrigation and non-irrigation functions.

Abstract: A method for decoloring sulfuric acid containing organic reatcives by which it is possible to obtain a crystalline sulfuric acid having a color index of less that 30 APHA unities, by adding controlled amounts of potassium chloride and hydrogen peroxide in a controlled environment.

Abstract: Described herein are several embodiments relating to modular irrigation controllers. In many implementations, the irrigation controllers are modular in that various functional components of the irrigation controller are implemented in removable modules that when inserted into position within the controller, expand the capabilities of the controller. Also described are various different types of expansion modules that may be coupled to the modular controller, having as variety of functions and features, as well as related methods of use and configuration of these modules in the controller. In one implementation, an expansion module is provided that includes a microcontroller capable of sending and receiving data communications to and from the a main microcontroller of the controller that executed irrigation programs, the data communications relating to an irrigation program.

Abstract: An irrigation controller includes a base unit with a removable and programmable control panel and backplane circuitry for communicating with a plurality of removable modules capable of performing a variety of irrigation and non-irrigation functions. A base module having irrigation station drivers is mated with the backplane circuitry and communicates with the base unit to carry out basic irrigation functions. A plurality of expansion modules and one or more smart modules, each having its own logic circuit, can be mated with the backplane circuitry to communicate with the base unit and carry out additional irrigation and non-irrigation functions.