Abstract: The invention provides a vacuum interrupter with improved separation of functional elements. The interrupter includes separable contacts for carrying continuous current and rod electrode arrays for carrying fault currents. The housing for the interrupter is evacuated, and has a plurality of interior chambers. The rod electrodes are in one chamber and the separable contacts are in an adjacent chamber. A communicating opening is provided between the chambers. The rod electrodes and separable contacts are connected in parallel in a common circuit. When the contacts are separated, arcing products are conveyed to the adjacent chamber through the communicating opening to initiate arcing between the rod electrodes.

Abstract: A stable, colored reference standard suitable for use in diagnostic determinations involving enzymatic reactions in which colorless 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride is reduced to the red-colored 1-(p-iodophenyl)-5-(p-nitrophenyl)-3-phenylformazan, is described. The reference standard of this invention is an aqueous solution containing, in specified amounts, 1-(p-iodophenyl)-5-(p-nitrophenyl)-3-phenylformazan; serum albumin; an N,N'-dimethylformamide or a dimethylsulfoxide solvent; and isopropyl alcohol. An inert bulking agent may be added to the aqueous colored standard and the solution obtained may then be lyophilized. The lyophilized form of the colored reference standard is stable for at least 3 months at 4.degree. C. and 24.degree. C. and can be easily reconstituted with water or with dilute aqueous hydrochloric acid solutions. The novel colored reference standard solution has an absorbence maximum of 500 nanometers.

Abstract: This electric circuit breaker comprises a plurality of vacuum-type circuit interrupters electrically connected in parallel with each other and means for opening the interrupters substantially simultaneously during circuit interruption. Each interrupter comprises an evacuated envelope and a pair of relatively-movable contacts located within the envelope to provide an inter-contact gap across which arcing can occur during circuit interruption. The stationary contacts of the two interrupters are respectively mounted on stationary contact rods that have their outer ends closely adjacent each other. A communicating passageway extends between the two inter-contact gaps through the stationary contacts and the stationary contact rods for conveying arcing products from any inter-contact gap that is then arcing to any that is not then arcing, thereby promoting concurrent arcing at said gaps during high-current interruptions.