Abstract: Known methods use the temperature of the water bath which surrounds the liquid sample as the adjusting parameter. The aim in these methods is to maintain the water bath at a constant temperature in order to fulfill the prerequisites for calibration. In contrast, in the inventive method a measurement is determined for the maximum permissible drift (?max) in the temperature of the water bath (?B) which is measured as the equivalent of the sample temperature (?P). This greatly simplifies the problem of adjusting the temperature which primarily arises as a result of the delays in the control circuit. The adjusting element need only recognize a drift (?) and correct the sum of the thermal currents which have occurred, to zero, allowing for a residual error (Prestmax) which results from a permissible contouring error (?B, ?B). The release of heat from the mixing propeller (Q) is used to obtain a rapid compensation.

Abstract: An insulating coating composition which is liquid or solid at normal temperature consists essentially of a normally liquid organic medium and a resin composition which is either a polyesterimide or a precursor of a polyester urethane and is soluble in the medium at 150.degree. C. The medium consists of 10% to 100% dimethyl phthalate, 90% to 0% conventional solvent for the resin composition, and 0% to 40% diluent.

Abstract: Polyester-polyimide resins having a hydroxyl value of 150 to 600 and containing repeating units derived from tris-(2-hydroxyethyl) isocyanurate or tris-(2-carboxyethyl) isocyanurate are known valuable film-forming agents in wire enamels. Enamels of low viscosity at high solids content can be prepared by dissolving the resins in solvent systems free from phenols and containing at least 30% (wt.) diacetylacetone, monoalkylesters of ethylene glycol, diethylene glycol and the like, and lower alkanoic acid esters of the ethers, and these solvent components are less irritating and partly less toxic than solvents employed heretofore.

Abstract: Lacquers of low viscosity at high solids content suitable for forming baked coatings on conductive wires which do not interfere with tinning and soldering of the coated wires consist essentially of a polyester of isophthalic or terephthalic acid having a hydroxyl number of 150 to 450, an isocyanate having isocyanato groups masked with .epsilon.-caprolactam, and of a solvent consisting essentially of at least one member of the group consisting of diacetone alcohol, lower alkyl ethers of ethylene glycol or diethylene glycols, and esters of said ethers with lower alkanoic acids, said lower alkyl having up to three carbon atoms, and said lower alkanoic acids having up to four carbon atoms.