Abstract: An optical system for exciting a temperature dependent phosphor with radiation and detecting independently emissions therefrom in optically isolable first and second wavelength ranges that gives an indication of the temperature of the phosphor. The optical system is carried by a heat-insulating housing disposed between a heat generating light source and the heat sensitive detectors. Dichroic mirrors are utilized to separate the two wavelength ranges emitted by the phosphor and to allow the sharing of a common optical path by three different radiation wavelength ranges without an undue loss of radiation intensity in any of the wavelength ranges. The light source may be of a helically shaped filament that is tilted with respect to an imaging optical axis so that the side of the helix is imaged with a minimum amount of the space between the turns showing, thereby maximizing the optical energy imaged from the light source.

Abstract: A technique of temperature measurement wherein an object or environment to be measured is provided with a phosphor material layer that emits at least two optically isolatable wavelength ranges whose intensity ratio depends upon the object or environment temperature, the emitted radiation being brought to a detector by an optical system that may include an optical fiber. Several specific applications of this technique are disclosed, such as temperature monitoring of electrical equipment and industrial processing, medical temperature instrumentation including the use of disposable elements that contain a small quantity of the temperature dependent phosphor, special and multiple probes, the use of liquid phosphors, and a phosphor paint for monitoring surface temperatures.

Abstract: The temperature measuring device comprises a rod which passes approximately vertically through the anode block and terminates at the level of the working face of the anode. Fitted over the rod at the top is a light plug which provides an optical connection to the fiber bundles with the minimum of reflection. This optical connection is usefully in a coupling fluid which, like the rod and the bundle of fibers, is able to transmit infra-red radiation.

Abstract: An infrared temperature probe for high pressure use is in the form of a hollow bolt adapted to be threaded into a complementary threaded aperture in the wall of a pressure vessel with the end thereof disposed flush with the internal surface of the pressure vessel wall. An infrared transparent window is secured in the end of the hollow bolt with one surface thereof disposed flush with the end of the bolt. A bundle of optical fibers is secured within the opposite end of the hollow bolt and a glass rod is mounted within the hollow bolt in operative relation to the window and the optical fiber bundle for transmitting infrared radiation from the window to the optical fiber bundle. The interior of the hollow bolt may be supplied with a circulating cooling liquid or gas.

Abstract: A thermometry system utilizes the thermally sensitive time dependent emission properties of luminescent materials. In one embodiment the system includes a probe constructed with an optic fiber bundle for conducting light both toward and away from the temperature sensitive luminescent element located at one end of the optic fiber bundle, a source for transient and/or modulated excitation of the temperature sensitive element, and a light responsive detection element located at the output end of the optic fiber bundle for detecting the transient and/or modulated light emissions by the luminescent temperature sensitive element. The emission signal received by the light responsive detector can be analyzed in a well defined manner to determine the temperature of the luminescent element and of any materials in thermal equilibrium with the luminescent material.

Abstract: A photoluminescent indicator apparatus having automatic feedback means to maintain the sensitivity of the indicator apparatus with respect to variations in environmental conditions. The apparatus includes a sample of photoluminescent material having a photoluminescent decay rate which varies as a function of environmental conditions. The sample is positioned in a remote location having some unknown aspect of the environment desired to be measured. The sample is optically excited with a modulating signal to generate an excitation output signal functionally dependent on the modulating signal and indicative of the unknown environmental condition. A phase detection means is provided for comparing difference in phase between a phase reference signal and the excitation output signal to generate a phase differential signal functionally related to the photoluminescent decay rate of the sample.

Abstract: In apparatus for picking up a test sample of molten metal or metal alloys and measuring the cooling curve of said sample, comprising a sample receptor and an optical conductor leading from the receptor to a transducer, the receptor is a small, open ended refractory tube having a cavity for receiving the molten sample arranged at the free extremity of a lance with the optical conductor contained within the lance and terminating at the cavity in said receptor and a barrier is disposed between the cavity and the optical conductor, the barrier consisting of a heat resistant, highly thermally conductive material of such quality as to cause the material of the melt sample which is picked up to adhere thereto.