Electric control devices for machine installations for the purification of fluids, in particular exhaust gases, gases or liquids, using spray nozzles, namely, electric control panels; electric controllers for installations in the nature of machines for the purification of fluids, in particular exhaust gases, gases or liquids, using spray nozzles; electric monitoring apparatus for installations in the nature of machines for the purification of fluids, in particular exhaust gases, gases or liqu...