Abstract: A method for producing two-component varnishes or paints involves withdrawing at least one colored basic varnish from a preselected source and introducing the varnish into a mixing zone, withdrawing a colorless hardener or cross-linking agent from another preselected source and introducing the hardener or cross-linking agent into said mixing zone, and maintaining a prescribed and previously adjusted mixing ratio between the varnish and the hardener or cross-linking agent by controlling the rate of flow of at least one component of the two-components, the basic varnish or the hardener or cross-linking agent, by a controllable metering means. The mixing ratio between the two components being determined by a means measuring a selected parameter of the mixture produced in the mixing zone. A suitable and measurable parameter of the mixture may be the electrical conductivity of the mixture, the dielectric constant of the mixture or the like.

Abstract: A process for controlling the nitriding effect of a nitriding bath of a salt melt containing alkali cyanate for the nitridation of iron and iron alloys wherein the nitriding effect of the bath is maintained in a specific range by determining the voltage occurring at an electrode of a solid electrolyte which conducts oxygen ions immersed in the nitriding bath.