Abstract: Apparatus for the measurement of unsteady gas temperatures comprises (a) a temperature probe having a sensing element. The sensing element has an optical interferometer optically coupled to one end of a first, addressing optical fibre. The interferometer has a first partially reflective surface defined at the end of the addressing fibre and a second partially reflective surface spaced from the first partially reflective surface by an optical path length I.

Abstract: A temperature measurement system for use in a thin film deposition system is based on optical pyrometry on the backside of the deposition substrate. The backside of the deposition substrate is viewed through a channel formed in the susceptor of the deposition system. Radiation from the backside of the deposition substrate passes through an infrared window and to an infrared detector. The signal output by the infrared detector is coupled to electronics for calculating the temperature of the deposition substrate in accordance with blackbody radiation equations. A tube-like lightguide shields the infrared detector from background radiation produced by the heated susceptor.

Abstract: The present invention relates to a totally novel device and process useful for the measurement of the temperature of a radiating body. More particularly, the present invention relates to a device that enhances the resolution and repeatability of the measured temperature of the radiating body by fitting a mathematical correlation to the emitted radiation spectra, generating calculated radiation intensities at specified wavelengths using the mathematical correlation, and then generating a suite of individual two-wavelength temperature values, which can be statistically evaluated and averaged for a final, measured temperature.

Abstract: The present invention relates to a fast bichromatic pyrometer for measuring the temperature T of a gas or of a moving surface, the pyrometer comprising: a measurement probe placed facing the surface or immersed in the gas and picking up thermal radiation that is characteristic of the temperature of said surface or of said gas; a single optical fiber connected to the measurement probe and transmitting said radiation; an optical block connected to the optical fiber and receiving said radiation, the optical block including inlet collimation means for transmitting all of said radiation, separation means formed by a dichroic slide for separating the transmitted radiation into two distinct spectral bands, and outlet focusing means for concentrating the two separated bands of radiation; a quantum detection circuit receiving said separated bands of radiation and converting them into two color voltages Vr, Vb; and a treatment circuit receiving the voltage signals and including analog-to-digital conversion means, a dig

Abstract: An infrared sensor is particularly well suited for the detection of heat sources, specifically from fires. It comprises an infrared detector receiving infrared radiation from a focused refractive optical unit. An optical chopper and electronic amplifier enable the sensor to operate without drift and with immunity to temperature changes in the sensor itself. The infrared radiation from the optical unit is appropriately filtered so as to optimize reception in a frequency band between 2.6 and 2.8 microns. In this band, there exists negligible energy from the sun due to absorption by gas molecules in the earth's atmosphere. Consequently, the sensor can be used in full sunlight without becoming saturated by the large magnitude infrared radiation of the sun. The sensor contains circuitry providing an audible output signal whose pitch is proportional to the intensity of the infrared radiation received from nearby heat sources. The device does not require any visual attention from a firefighter.

Abstract: Apparatus for automatic cooking of a cooking object in a cooking apparatus, such as a microwave oven, in which a surface temperature of the cooking object is accurately detected for automatic cooking of the cooking object, is disclosed, including infrared radiation extracting part having an angle of view of a predetermined form toward one side of the turntable for extracting an infrared radiation radiated from a surface of a cooking object; and temperature detecting part having a window with an elliptical angle of view for reception of the infrared radiation for detection of a temperature of the surface of the cooking object.

Abstract: A rapid thermal heating apparatus in which lamps are disposed in a plurality of light pipes arranged to illuminate and supply heat to a substrate. The light pipes are positioned so that the illumination patterns overlap. The energy supplied to the lamps is controlled to provide a predetermined heating pattern to the substrate. A liquid cooled window cooperates with the light pipes to transmit energy to a wafer disposed in an evacuated chamber.

Abstract: Method and apparatus provided for visibly outlining the energy zone to be measured by a radiometer. The method comprises the steps of providing a laser sighting device on the radiometer adapted to emit at least one laser beam against a surface whose temperature is to be measured and positioning said laser beam about the energy zone to visibly outline said energy zone. The apparatus comprises a laser sighting device adapted to emit at least one laser beam against the surface and means to position said laser beam about the energy zone to visibly outline said energy zone. The laser beam may be rotated about the periphery of the energy zone. In another embodiment, a pair of laser beams are projected on opposite sides of the energy zone. The laser beam may be further pulsed on and off in a synchronized manner so as to cause a series of intermittent lines to outline the energy zone. Such an embodiment improves the efficiency of the laser and results in a brighter laser beam being projected.

Abstract: A sensor for measuring the temperature of a workpiece including a substrate, wafer, shield or other element in a semiconductor processing system. In the illustrated embodiment, the sensor has a heat shield to reflect away from the heat sensing element, heat from unwanted sources such as susceptors and heating cartridges which can adversely affect the accuracy of the measurement. In addition, the heat shield preferably has a small thermal mass for improved responsivity.

Abstract: A method and apparatus for measuring thermal properties of electronic components (25) encapsulated in packaging is described. The method can be used to measure a junction temperature T.sub.j of the electronic component (25), without removing the package (30), and during operation of the electronic component (25) by a power supply.

Abstract: The invention relates to a method and its implementation for the rapid calibration of thermoelements, preferably in the temperature range from 700.degree. C. to 1800.degree. C. The calibration apparatus consists of commercially available components, is therefore comparatively very economical, light and portable; the energy consumption is low, because the conventional heating chamber can be eliminated. Errors of the first and second kind associated with the thermoelements to be calibrated are detected.

Abstract: In an electrical resistive-load battery testing system, apparatus and methods disclosed for independently monitoring and reacting to both the temperature of the load and the power actually consumed by the load. The signals derived by the temperature and power monitoring aspects of the invention may be used for any useful purpose including visual and/or audible indicators to alert an operator that the system has exceeded predetermined operating levels. The load may be of a carbon-pile construction, though other loading arrangements are possible. The load-temperature monitoring aspect to the invention includes an optical sensor supported to receive thermal radiation from the load, and output an electrical signal representative of the level of radiation emitted by the load. Means connected to receive the electrical signal from the optical sensor are further provided to perform an operational function if the level of radiation emitted by the load exceeds a predetermined value.

Abstract: A method of monitoring the temperature of a target (4), the method comprising:a) sensing radiation emitted by the target (4) at at least two different wavelengths;b) determining a temperature value from the sensed radiation in accordance with a first predetermined algorithm;c) repeating steps a) and b) a number of times to generate a set of temperature values;d) selecting a target temperature from the set of temperature values in accordance with a second predetermined algorithm; and,e) generating an output signal defining the target temperature obtained in step d).

Abstract: Disclosed are four improvements in temperature-measuring radiometric equipment. The first improvement is directed to increasing the sensitivity of a radiometer by employing microwave noise power derived from a reference noise source in an amount that corresponds to a temperature higher than that of the specimen, and applying the reference-noise-source-derived microwave noise power as an input to the radiometer for a shorter time than is microwave noise power derived from a specimen. The second improvement is directed to reducing emissivity error by employing open-loop means comprising a microwave circulator for applying microwave noise power generated by at least one resistor thermostatically heated to a temperature in the neighborhood of the temperature of a patient's body tissue back to the body tissue.

Abstract: There is provided a method of measuring thermal diffusivity of solids and electronic lifetimes and defect properties of semiconductors useful for in-situ, non-destructive monitoring of engineered materials and electronic substrates. The method, termed photothermal rate window method, involves irradiating a sample with a repetitive square laser pulse of duration .tau..sub.p and period T.sub.0 and monitoring the temperature profile by measuring the photothermal signal emitted from the sample. The period T.sub.0 of the repetitive heating pulse is maintained constant and the pulse duration .tau..sub.p is varied in the range between 0 and T.sub.0 with the temperature measured at each value of .tau..sub.p. The method of measuring semiconductor recombination lifetimes involves irradiating a sample and scanning one of either the period T.sub.0 and the pulse duration .tau..sub.p of the repetitive laser pulse with the other held constant. The photothermal signal emitted from the surface is measured.

Abstract: A housing having a base having a cavity within which a temperature scanner module may be mounted and which is readily clamped to a rail of a railroad track so that a scanner may detect an over-heated wheel or wheel bearing. The base includes a rail clamp support portion for extending beneath the rail. A clamping assembly is positioned on the clamp support portion with resilient compressible bumpers sandwiched therebetween. The clamping assembly includes a first rail clamp and a pair of spaced apart arms between which a second rail clamp is positioned and adjustably attached to the first clamping assembly so as to secure the assembly to a rail. The arms of the clamping assembly terminate at locations above the upper surface of the clamp support portion and may be forcibly urged to apply a bending moment to the clamping assembly adjacent the cavity to pivot the clamping assembly on the bumpers relative to the base. The base may thus be angularly adjusted relative to the rail.

Abstract: A radiation thermometer assembly comprises a radiation thermometer for detecting radiation and for generating at a first terminal an electrical output signal representative of the detected radiation. A cap assembly comprises a housing carrying a second terminal to which a cable can be connected, and electrical connectors to electrically couple the first and second terminals. An overcenter latch removably secures the cap assembly to the radiation thermometer.

Abstract: Temperature of a subject is continuously monitored using a remote sensor assembly mounted in a subject's ear canal. The remote assembly connects to a display housing which contains the temperature display and supports electronics for responding to the sensed radiation. In one configuration, the major components of the remote assembly include a radiation detector, a plug structure and a flexible extension. The radiation detector has a thermopile and a first temperature sensor in close thermal contact with a thermopile junction. The flexible extension connects the radiation detector with the plug structure. Because the flexible extension bends to the contours of an ear canal, the remote sensor assembly extends well into a subject's ear canal without discomfort. The plug structure is molded to fit securely in the concha region of an ear canal and includes a second temperature sensor which senses the temperature therein.

Abstract: A light detector is disclosed for measuring the temperature of an object. The light detector includes a lens assembly for accepting light emitted from the object, an aperture, and a mirror for reflecting the infrared energy of the object into a fiber optic cable. The fiber optic cable is connected to a depolarizing element to which pressure is externally applied. The depolarization element relays the infrared energy into a detection portion and a signal processing portion for calculating temperature. Before the infrared light enters the fiber optic cable, a chopper, controlled by a driving circuit, chops the infrared energy reflected by the mirror.

Abstract: A method and apparatus for optical pyrometry in a Rapid Thermal Processing (RTP) System, whereby the radiation used to heat the object to be processed in the RTP system is in part specularly reflected from specularly reflecting surfaces and is incident on the object with a particular angular distribution, and the thermal radiation from the object is measured at an angles different from the angle where the incident radiation specularly reflected from the surface of the object is a maximum.

Abstract: A system for aiming a remote IR temperature sensing device includes a beam splitter assembly and mirror assembly mounted on opposite sides of the body of the device. Both assemblies provide for adjusting the vertical and azimuthal positions of alignment beams to facilitate the use of inexpensive, low-tolerance parts while providing high accuracy to improve sensitivity, accuracy, and resolution. A dual action trigger initiates temperature measurement and logs currently measured temperature information.

Abstract: The apparatus is a thermal detector which uses an active detector element and a compensator detector element, particularly in a voltage divider configuration. Radiation from a scene of interest impinges on the active detector element and radiation from an electronically modulated light source impinges on the compensator detector element.

Abstract: A radiation thermometer comprises an optical objective through which radiation to be detected passes. A beam splitter has a central region through which a central portion of the radiation which has passed through the objective passes undeflected and an outer region which reflects radiation surrounding the central portion. An eye piece receives radiation passing through the beam splitter; and a radiation detector receives radiation reflected by the beam splitter.

Abstract: A contamination-resistant, temperature-sensing device for sensing the extent of conductive heat flow from a metal surface. A heat transfer member is mounted to one end of a thermally insulative tube. The heat transfer member has two oppositely facing surfaces, one of which engages the metal surface to receive conductive heat flow therefrom, the other of which radiates transferred heat through the tube. A sensor is mounted to the other end of the tube to detect the extent of heat radiated through the tube and hence the extent of conductive heat flow from the metal surface. The sensing device also includes a housing surrounding the tube and the sensor. In addition, the sensing device includes a variable rate coil spring to allow the heat transfer member to bear against the metal surface at a constant contact force. A controller is electrically coupled to the sensor for controlling the extent of conductive heat flow from the metal surface based on the detected heat radiated through the tube.

Abstract: Devices relating to a psychrometer employing an infrared thermocouple aimed at a wet surface, and another infrared thermocouple aimed at a dry surface, are described. The wet surface is continuously supplied with liquid, for example, H.sub.2 O. The infrared thermocouple which is aimed at the wet surface detects evaporative heat loss instantaneously at the wet surface as it occurs, without coming into contact with the wet surface.

Abstract: Temperature nonuniformity across a semiconductor wafer during both the transient and steady state of a typical rapid thermal processing (RTP) cycle has been a deterrent in using RTP in many VLSI unit processes. The present invention consists of a three-dimensional mathematical model to study the temperature variation across a wafer in an RTP oven for given lamp power settings, during both the transient and steady state of a typical thermal cycle and control a heating lamp back by a computer program. The simulation package has been written in FORTRAN, and the validity of various models have been checked by performing a series of oxidation experiments.

Abstract: A method for determining characteristic features of processes forming radicals by sensing the temperature and/or the concentration of radicals with detectors in zones that are monitored by at least 2 detectors.

Abstract: A temperature measurement system for use in a thin film deposition system is based on optical pyrometry on the backside of the deposition substrate. The backside of the deposition substrate is viewed through a channel formed in the susceptor of the deposition system. Radiation from the backside of the deposition substrate passes through an infrared window and to an infrared detector. The signal output by the infrared detector is coupled to electronics for calculating the temperature of the deposition substrate in accordance with blackbody radiation equations. A tube-like lightguide shields the infrared detector from background radiation produced by the heated susceptor.

Abstract: A thermal difference detector for testing serviceability of a heat source includes a sensor connected via an amplifier-filter to a microprocessor outputting an indicator. The inventive detector can be used in a system for testing the serviceability of a plurality of heat sources. The system comprises a plurality of detectors, a robotic structure, with the detectors mounted on arms of the structure, a microprocessor and an indicator unit. A method is also disclosed comprising a sequence of steps including detecting radiation from an ambient temperature source, detecting radiation from the heat source, transforming them into electrical signals and processing the signals, comparing them to each other, and making a judgement of the serviceability of the heat source based on a predetermined criteria.

Abstract: A high temperature, short time microwave heating system 10 for heat-sensitive liquid material to inactivate or reduce pathogenic agents or organisms, such as viral contaminants. The system 10 includes a disposable cartridge 26 consisting of a preheater 32, a microwave heating coil 56 and cooler 58 with the heating coil 56 adapted to be easily inserted in and removed from the microwave heating field.

Abstract: Method and apparatus are provided for visibly outlining the energy zone to be measured by a radiometer. The method comprises the steps of providing a laser sighting device on the radiometer adapted to emit at least one laser beam against a surface whose temperature is to be measured and positioning said laser beam about the energy zone to visibly outline said energy zone. The apparatus comprises a laser sighting device adapted to emit at least one laser beam against the surface and means to position said laser beam about the energy zone to visibly outline said energy zone.

Abstract: A computer controlled system for real-time control of semiconductor wafer fabrication process uses a multi-point, real-time, non-invasive, in-situ pyrometry-based temperature sensor with emissivity compensation to produce semiconductor wafer reflectance, transmittance, and radiant heat energy measurements. The temperature values that the sensor determines are true temperatures for various points on the wafer. The process control computer stores surface roughness values for the semiconductor wafer being examined. The surface roughness values are produced by surface roughness sensor that makes non-invasive and in-situ measurements. The surface roughness sensor performs roughness measurements of the semiconductor wafer based on coherent reflectance and scatter reflectance of the wafer. Based on surface roughness measurements, the process control computer can use the real-time, in-situ measurements of the multi-point pyrometry-based sensor to obtain real-time measurements of time wafer temperature distribution.

Abstract: Thermal, optical, physical and chemical characteristics of a substrate (11) surface are determined with non-contact optical techniques that include illuminating (23) the surface with radiation having a ripple intensity characteristic (51), and then measuring the combined intensities (53) of that radiation after modification by the substrate surface and radiation emitted from the surface. Precise determinations of emissivity, reflectivity, temperature, changing surface composition, the existence of any layer formed on the surface and its thickness are all possible from this measurement. They may be made in situ and substantially in real time, thus allowing the measurement to control (39, 41) various processes of treating a substrate surface. This has significant applicability to semiconductor wafer processing and metal processing.

Abstract: A radiation clinical thermometer includes a moveable probe which actuates a start switch when inserted into a patients ear. The radiation clinical thermometer also includes a probe cover device for dismounting a probe cover from the probe. The probe cover device is operatively connected in circuit with the start switch to only allow operation of the thermometer when the probe cover device is in a position indicating that a probe cover is mounted on the probe. The thermometer also includes time delay devices which preclude operating the thermometer unless the start switch or the probe cover detection device is in a predetermined position for a predetermined amount of time.

Abstract: Temperature of a subject is continuously monitored using a remote sensor assembly mounted in a subject's ear canal. The remote assembly connects to a display housing which contains the temperature display and supports electronics for responding to the sensed radiation. In one configuration, the major components of the remote assembly include a radiation detector, a plug structure and a flexible extension. The radiation detector has a thermopile and a first temperature sensor in close thermal contact with a thermopile junction. The flexible extension connects the radiation detector with the plug structure. Because the flexible extension bends to the contours of an ear canal, the remote sensor assembly extends well into a subject's ear canal without discomfort. The plug structure is molded to fit securely in the concha region of an ear canal and includes a second temperature sensor which senses the temperature therein.

Abstract: A non-contact temperature measuring system and a dual-reference body structure employed therein is described, wherein a moving object whose temperature is to be determined, is passed by first and second reference bodies having a same form factor with respect to the moving object. Each of the reference bodies has a heat flow sensor embedded at the end of a cavity formed in the reference body such that the heat flow sensor primarily responds to radiation heat flow generated by a temperature differential between the moving object and its respective reference body.

Abstract: A real-time multi-zone semiconductor wafer temperature and process uniformity control system for use in association with a semiconductor wafer fabrication reactor comprises a multi-zone illuminator (130), a multi-point temperature sensor (132), and process control circuitry (150). The method and system of the invention significantly improved wafer (60) temperature control and process uniformity. The multi-zone illuminator module (130) selectively and controllably heats segments of the semiconductor wafer (60). Multi-point temperature sensor (132) independently performs pyrometry-based temperature measurements of predetermined points of the semiconductor wafer (60). Process control circuitry (150) operates in association with the multi-zone illuminator (130) and the multi-point temperature sensor (132) for receiving the temperature measurements and selectively controlling the illuminator module to maintain uniformity in the temperature measurements.

Abstract: A method for measuring and adjusting the temperature of surface ice in artificial ice rinks, in which water is frozen to ice with the aid of refrigerating channels arranged in the rink and through which refrigerant is passed a by means of a refrigerating system and wherein the temperature of the ice is controlled by controlling the refrigerating power of the refrigerating system. The method is mainly characterized in that the surface ice temperature is measured with the aid of at least one sensor, which functions to measure infrared radiation from the surface ice. The signals produced by the sensor are processed in a control unit which controls the refrigeration system in a manner to bring the surface ice to a predetermined temperature. The invention also related to an arrangement for carrying out the method.

Abstract: An improved probe cover and thermometer for tympanic temperature measurement include means to preclude the reuse of a probe cover. In the preferred embodiment, a cup-shaped probe cover includes two or more legs terminating in tabs or flanges. The tabs or flanges are sensed by switches. In the preferred embodiment, the switches are disposed within a recess, thereby precluding the circumvention of the switch function. In an alternative embodiment, a plurality of externally located switches are provided to mate with a plurality of flanges. Alternative, the extension from the probe cover may comprise a skirt terminating in a flange or tab. In operation, the thermometer may not be operated without the positive presence of a probe cover, as indicated by the presence of the tabs acting upon the recessed switch or a plurality of tabs acting upon the externally located switches. Ejection of the probe cover causes deformation of the probe cover to indicate prior use.

Abstract: A position housing assembly, for a generally cylindrical infra-red thermocouple sensor of the type having a sensing face at one end and one or more electrical conductors extending from the other end, includes a cylindrical housing having a central bore for telescopically receiving a sensor. A conical reflective surface, at one end of the housing, concentrates infra-red rays toward the face of the sensor; the reflective surface may be integral with the housing or it may be carried by a separable adapter. A separable handle attaches to the housing, and extends into the housing wall for guiding conductors from a sensor to the exterior of the housing. A set screw on the housing clamps the sensor within the central bore. Adjustable positioning legs extend axially from the housing to position it relative to a test surface. In one embodiment the legs are attached to a moveable positioning bracket, while in another, the legs slide within axial bores integrally formed in the housing.

Abstract: A radiation detector comprises an extension shaped to be comfortably positioned in an outer ear area for obtaining temperature indications without discomfort to the subject. The extension increases non-linearly in diameter along a portion of its distal end forming a rounded distal tip. The extension is positioned in an ear canal such that the rounded tip is disposed at the opening to the ear canal. An infrared radiation sensor is positioned in the detector for receiving radiation emitted from the ear canal. An electronics unit converts the received radiation to a temperature indication.

Abstract: Apparatus and method for non-contact temperature measurement of a film growing on a substrate which accounts for the change in emissivity due to the change in film thickness. The system employs an adaptively calibrated pyrometer wherein the substrate emittance is continuously computed so that the temperature measurement is accurate regardless of the emittance variation. The new system is easily constructed by adding data processing system software and hardware to conventional pyrometers.

Abstract: A thermal condition sensor system monitors equipment such as aircraft engines. The thermal condition sensor system includes a collector which collects radiation from the equipment and a detector assembly which detects collected radiation over a discriminating spectral band region in at least three spectral bands and generates signals representative of detected radiation in each spectral band. A processor receives the signals and generates a report of the thermal conditions of the equipment using interband comparison of the at least three spectral bands.

Abstract: A temperature measuring device for a gasifier of a gasifier system wherein the gasifier has a through opening formed thereon. The temperature measuring device includes a slag shield mounted on the gasifier so that a portion of the slag shield extends into the interior of the gasifier through the opening with which the gasifier is provided for this purpose, and a temperature measuring instrument mounted in supported relation within the slag shield so that a line-of-sight exists from the temperature measuring instrument into the interior of the gasifier whereat the temperature is desired to be measured. The slag shield is designed to protect the temperature measuring instrument from the slag flow within the gasifier.

Abstract: A thermal infrared detector comprising a dielectric pellicle suspended over a cavity in a substrate, the pellicle supporting a detector element comprising a heat sensitive semiconductor layer between a pair of thin fim metallic contracts, these being deposited on the pellicle, the cavity being formed by etching and removal of the substrate material through holes or slots in the surface of the substrate.

Abstract: Method and apparatus are provided for visibly outlining the energy zone to be measured by a radiometer. The method comprises the steps of providing a laser sighting device on the radiometer adapted to emit at least one laser beam against a surface whose temperature is to be measured and positioning said laser beam about the energy zone to visibly outline said energy zone. The apparatus comprises a laser-sighting device adapted to emit at least one laser beam against the surface and means to position said laser beam about the energy zone to visibly outline said energy zone.

Abstract: A system is disclosed for externally measuring the temperature of a substrate having a reflective surface within a chamber. The system comprises a first light source having sufficient intensity for bombarding the reflective surface with photons, thereby heating the surface. The first light source has an output level and a wavelength substantially in the absorption band of silicon. The system also comprises means for exposing the substrate to a gas in order to form a layer superjacent the reflective surface. A sensor, preferably a photo detector, for sensing changes in the reflectivity of the surface is included. In one embodiment of the present invention, the sensor comprises a second light source and a sensor, for sensing the reflectivity of the surface caused by the reflecting photons. Furthermore, the system comprises control circuitry for controlling the first light source in response to the sensor; the control circuitry being coupled to the sensor by a feedback loop.

Abstract: Temperatures along the surfaces of water tubes in an operating steam boiler are determined by detecting infrared radiation emitted from the tube surfaces in one or more narrow pass-bands founds to be available despite the presence of hot and turbulent flue gases between the sensor and the tube surface to be measured.

Abstract: A remote temperature and/or temperature difference measuring device which includes a measuring circuit having a heat flux sensor for sensing the heat flow from an area on the surface of a body, and a portable housing which supports the sensor and also a device for determining or marking the area of analysis. The measuring circuit includes the heat flux sensor, a memory circuit connected to the heat flux sensor, and a storage input device such as a push button for initiating, at any given moment, the memory circuit's storage of a reference signal from the heat flux sensor. The measuring circuit also includes a comparator of which one of the inputs receives the output signals from the heat flux sensor, while the other input is connected to the memory circuit providing the reference signal. The comparator thus outputs a signal which corresponds to the difference between the reference signal and a subsequently received heat flux sensor output signal.

Abstract: A radiation detector with temperature readout has a multicolored LED display divided into segments of zero degrees to 9 degrees centigrade colored green, 10 degrees to 19 degrees centigrade in yellow, and 20 degrees to 100 degrees centigrade in red. Alternatively, two red segments are provided for ranges of 20 degrees to 64 degrees centigrade and 65 degrees centigrade and above, respectively. The radiation detector is automatically zeroed at ambient upon use and provides a readout of temperature rise above ambient throughout a scan of a subject. In one design, only one LED for each segment of the display is illuminated at a time. An audible signal is sounded at an increasing pulse frequency as the display is illuminated from the green segment to the red segment of measured temperature rise above ambient with a constant tone for temperature rises above about 20 degrees centigrade. In an alternative design a timing circuit allows the detector to self operate for a predetermined length of time.