Temperature measuring method using radiation thermometer

A temperature measuring method of measuring a temperature of an object by a radiation thermometer capable of approximating the relation between its output and an actual temperature of the object by a predetermined straight line and of being calibrated by properly determining a slope and a y-intercept for the straight line, said measuring method comprising the steps of:

• (a) preparing a plurality of objects differing from each other in surface condition and measuring a reflectivity of each object regarding the light of a wavelength that is not transmitted by the same object;
• (b) determining a slope and a y-intercept for a proper straight line for each object;
• (c) determining the relation between the reflectivity of the object, and the slope and y-intercept of the proper straight line on the basis of the determined slope and y-intercept of the straight line for each object and the measured reflectivity of each object;
• and
• (d) calibrating the radiation thermometer on the basis of the relations and determining the temperature of the object with the calibrated thermometer;
• wherein the step of determining a slope and a y-intercept for the straight line comprises the steps of:
• i. setting a plurality of slopes and a plurality of y-intercepts for the straight line,
• ii. measuring temperature by the radiation thermometer by using each of the slope and y-intercept for the straight line and subjecting each object to a predetermined process that provides a result corresponding to process temperature by two recipes;
• iii. expressing the result of processing by an equation as a function of the slope and y-intercept of the straight line for each recipe;
• iv. determining a reference value of the result of processing for each recipe;
• and
• v. calculating a slope and y-intercept for a proper straight line for the by substituting the reference value into the equation fro each recipe.