Abstract: A continuous oxygen content monitor has a reference electrode embedded in a powdered chrome-chrome-oxide mixture and a counter electrode embedded in an elongate alumina-graphite sleeve which acts as the probe support body. Two hallow and spacer ablative steel domes encase the reference electrode and an intermediate air gap spacing and provide insulation to prevent thermal shock from damaging the monitor during insertion into the metal melt. A circuit provides counter emf across the sensing electrodes to prevent ion depletion of the reference material.

Abstract: A fluidic sound amplification system couples successive laminar proportional amplifiers through acoustic radiation between output and input horns to avoid the propagation of null offset signals. A second approach to obviating DC null bias in a fluidic sound amplification system comprises splitting the input signal, effecting a selected time delay on a portion of the signal such that the bandpass frequencies and dead zones or cancellation frequencies respectively of the amplified signals are 180.degree. out of phase and combine to produce a near uniform frequency response. A third approach is to use multiple parallel elements in each stage of amplification in such a manner that mechanical errors cancel each other out.

Abstract: A thermocouple assembly for sensing temperatures of molten metals in a metallurgical vessel, such as a tundish used in continuous steel casting, includes a double bore insulator containing the two noble metal alloy lead wires of the thermocouple. Platinum-rhodium alloys are preferred. The weld bead joining the ends of the leads or hot junction of the thermocouple is positioned within one of the bores of the insulator such that a lower purity alloy lead is exposed in the loop. The loop resides in a blind bore formed in the end of the double bore insulator and is enclosed in a containmemt zone by a refractory plug or foil disc closing off the end of the blind bore. The double bore insulator is received in an axial bore of a refractory sheath having a closed end adjacent the loop area of the thermocouple.

Abstract: Disclosed is a protective thermocouple sheath of a magnesia graphite refractory material for use in continuous temperature measurements of molten metal in a metallurgical ladle and having a basic slag layer thereon. The sheath includes an elongated torpedo-shaped sheath body formed of a refractory composition and having an interior borehole extending axially therethrough and adapted to receive a thermocouple. The sheath body includes a lower end which is closed about the borehole and forms a narrow, tapered tip. The sheath body also includes a first body portion integral with the tapered tip and having a relatively constant cross section and providing a thin wall around the borehole. The sheath body also includes a second body portion having a relatively constant cross section larger than the cross section of the first body portion and providing a thicker wall around the borehole. The borehole terminates in an open end at the second body portion.

Abstract: A null balanced fluidic sensing system that is less susceptible to pressure upply disturbances includes sensing and amplifying elements in a closed loop arrangement. The differential output of the sensor, developed as a result of an input stimulus, is fed into the inputs of a single sided amplifier. The output of the amplifier is used as a source of supply for the sensor. This closed loop arrangement uses the null offset characteristics of the elements to create a null balanced fluidic sensing system.

Abstract: A protective sheath for a temperature sensing device for use in determining the temperature of molten metals. The temperature sensing device, such as a thermocouple, is encased in a molybdenum tube which is coated with successive porous layers of molybdenum, a plurality of layers of Al.sub.2 O.sub.3 -Cr.sub.2 O.sub.3 -Mo in a decreasing concentration of Mo in proceeding from the inner to the outer layers, and a layer of substantially pure Al.sub.2 O.sub.3 -Cr.sub.2 O.sub.3. The Al.sub.2 O.sub.3 -Cr.sub.2 O.sub.3 layer may be covered with an outer coating of a material, such as boron nitride, to protect the Al.sub.2 O.sub.3 -Cr.sub.2 O.sub.3 layer from attack by slag. Alternating layers of Al.sub.2 O.sub.3 -Cr.sub.2 O.sub.3 and boron nitride may be applied as outermost sacrificial layers.

Abstract: A protective sheath for a temperature sensing device for use in determining the temperature of molten metals. The temperature sensing device, such as a thermocouple, is encased in a molybdenum tube which is coated with successive porous layers of molybdenum, a plurality of layers of Al.sub.2 O.sub.3 --Cr.sub.2 O.sub.3 --Mo in a decreasing concentration of Mo in proceeding from the inner to the outer layers, and a layer of substantially pure Al.sub.2 O.sub.3 --Cr.sub.2 O.sub.3. The Al.sub.2 O.sub.3 --Cr.sub.2 O.sub.3 layer may be covered with an outer coating of a material, such as boron nitride, to protect the Al.sub.2 O.sub.3 --Cr.sub.2 O.sub.3 layer from attack by slag. Alternating layers of Al.sub.2 O.sub.3 --Cr.sub.2 O.sub.3 and boron nitride may be applied as outermost sacrificial layers.

Abstract: An immersion pyrometer having an outer casing comprising a mixture of graphite and a refractory metal oxide for contact with molten metal, an inner sheath enclosed by said outer casing, said inner sheath comprising a closed end metal tube wherein the closed end is in heat transfer contact with said outer casing, and a thermocouple within said inner sheath.

Abstract: A mechanically offset fluid amplifier for converting the absolute pressure f a pressurized fluid to a differential pressure indicating the pressure of the pressurized fluid relative to a predetermined set point pressure. The device includes two outlets separated by a splitter, a supply nozzle for directing a jet of the pressurized fluid toward a first of the two outlets at a velocity determined by the absolute pressure, and control elements for deflecting the jet toward the second outlet such that as the jet velocity increases from zero, the deflection of the jet increases to a maximum value and then decreases until the differential pressure between the two outlets is equal to zero when the absolute pressure of the pressurized fluid is equal to the predetermined set point pressure.