Abstract: A method and a device are disclosed for measuring the lithium concentration in the primary cooling circuit of a nuclear power station reactor. The lithium concentration Li.sup.+ is determined by linear correlation between the electrical conductivity .lambda. of the cooling water measured by measuring means 1, at a given temperature t measured by measuring means 2. Means 4 to measure the boron concentration B make it possible, by means of the computing means 3 to determine the lithium concentration Li.sup.+ according to the decreasing lithium hydroxide specification. The invention can be applied to the maintaining and regulation of the pH of the cooling water of a nuclear power station reactor at a determined value.

Abstract: The present invention relates to a process and system for continuously monitoring and calculating the flow rate of a fluid medium in a flow line. The system includes a camera for viewing and capturing an image of a chart having different colored trace lines representing manometric pressure upstream of an orifice in a plate in the flow line and differential pressure across the orifice plate, a color filter for creating a modified image of the chart, an electronic digitizer for digitizing the images, and a microprocessor for determining the fluid flow rate from the captured and/or modified images. The system also includes monitors for displaying any of the iamges and manually operated devices for editing the images and for providing the microprocessor with instructions.