摘要 |
<p>A system and method for producing and maintaining a predetermined proportionate mixture of two fluids, such as water and foam concentrate, in accordance with conductivity measurements of the fluids. A set point is established which is representative of the conductivity of the predetermined proportionate mixture. The conductivity of the mixture is measured and compared with the set point by conductivity probes and a microprocessor. A control valve is continuously adjusted to maintain the predetermined proportionate mixture in response to control signals from the microprocessor in accordance with the comparisons of the conductivity values. <IMAGE></p> |