Abstract: A device for continuously delivering a proportionately constant fire-fighting solution which comprises an extinguisher foam mixed with variable flow rates of fire fighting water. The device comprises a motor, which is a volumetric screw pump driven in reverse by the hydraulic pressure of the fire fighting water network. This hydraulic motor is mechanically connected to one or more volumetric pumps which proportionally meter the fire fighting foam extinguisher liquid into the network water.

Abstract: An apparatus for generating electric signals simulating the output of a device for measuring physical variable comprises a selector for choosing the type of measuring apparatus to be simulated, a measuring unit selector, a selector for selecting the value of a physical variable the measurement of which is to be simulated, a computer circuit controlled by the selectors and including a memory to contain information concerning the types of measuring apparatus that can be selected, and a device controlled by the computer circuit for supplying a simulated output signal to output terminals.