9 measurers, checkers, signalers and documentors, namely, electronic sensors for measuring system contamination in hydraulic and lubricating systems; electronic filtering units for the checking of oil condition, maintenance, oil service, and for measuring system contamination in hydraulic and lubricating systems, including and electric vacuum pump and filtration unit; electronic and optical controls and regulators in the fields of fluid, sensor, environmental and process technologies, namely, data processors, computers, data loggers, microprocessors, software for use in analyzing system contamination in hydraulic and lubricating systems, and computer printers