Abstract:
A thermal radiation sensor is joined with a shutter that is adapted for reversible interruption of radiation from an object to the sensor. The shutter includes an integral electrically operated heater for maintaining a portion of the shutter at a predetermined temperature as a thermal reference for the sensor. The sensor is alternatively exposed to radiation from the object and the thermal reference portion of the shutter, and provides a first signal representative of the radiation that it receives from the object and a second signal representative of the radiation that it receives from the reference portion. An electronic circuit is connected to the sensor for receiving the first and second signals, for calculating the temperature of the object, and for providing a signal representative of the calculated temperature.
Abstract:
An improved method and apparatus are disclosed for calibrating the emissivity characteristics of a semiconductor wafer within a processing chamber by supporting a sample wafer on a graphite susceptor within the chamber and by comparing the temperature measured within the susceptor in close proximity to the center of the wafer with the temperature measured by the emission of radiation from the surface of the wafer through the walls of the processing chamber. Temperature measurements subsequently made from the radiation emitted from the surface of similar wafers are corrected with reference to the measurement made of the temperature within the susceptor on the sample wafer.
Abstract:
When a steel sheet or the like is heated in a furnace to a temperature somewhat higher than the room temperature and is still or moved, its temperature can be measured by detecting the radiant energy therefrom. The measurement is normally difficult due to the influence of background noise of radiant energy from the surroundings, change of the transmittance factor of the environment or atmosphere for radiant energy, and change of the emissivity of the object to be measured. In order to remove such causes of errors and to correctly measure the temperature by detecting radiant energy, a radiometer and a black body radiator are disposed symmetrically and specularly with respect to the normal to a surface of an object to be measured, and two different amounts of radiant energies are emitted from the black body radiator, and the emissivity of the object to be measured is determined from the detected values from the radiometer, the two temperature values of the black body radiator, and the diffusely reflecting factor associated with the object to be measured, whereby correct measurement of the surface temperature of the object to be measured can be done. Embodiments for implementing this method are proposed.
Abstract:
Es wird eine Vorrichtung und ein Verfahren vorgeschlagen, wobei ein wärmesensierendes Element (1) eine Absorberschicht (3) aufweist, welche elektrisch leitend vorgesehen ist.
Abstract:
Disclosed is a method for testing whether a radiation measuring apparatus comprising a heatable or coolable radiation incidence window (W) functions properly. According to said method, a modification (?U W ) of the sensor signal (U) is detected and analyzed in accordance with the window temperature (T W ) during a heating or cooling process. The difference ?U = |U 2 -U 1 | between two test signals (U 1 and U 2 ) which represent the temperature (T b ) of any test object and are recorded at two different temperatures (T W1 and T W2 ) of the radiation incidence window (W) can be used as a measure for said modification, for example. Said difference is compared to a predefined reliability value or tolerance range within which the radiation measuring apparatus is guaranteed to function properly. A fault is signaled in case there might be a deviation. Preferably, the user is also provided with an indication as to the type of the detected fault, such as a dirty radiation incidence window (W) or a calibration error, as well as a tip or a possibility on how to correct said fault. A detected calibration error can also be corrected automatically if necessary. The invention further relates to a radiation measuring apparatus, i.e. an infrared radiation thermometer, for carrying out said method.