PURPOSE: To enable the highly precise measurement of a rate of thermal expansion of a material to be measured, by measuring the dimensions of the material from the position of a table and an output signal of a photosensing element which varies with the movement of the table.
CONSTITUTION: When the temperature of a material 7 to be measured in a heating furnace 5 rises to a prescribed temperature and a table 3 moves onto the right side, a laser light reaches a photosensing means 2 until the optical path 6 thereof coincides with the left edge A of the sample 7. When the laser light reaches the left edge A of the material 7 and an output of the photosensing element 12 decreases to a threshold level, a comparator 22 regards the laser light as reaching the left edge A of the sample 7 and inputs a signal detected on the occasion to CPU 14. Meanwhile, a linear scale 23 receives a position signal as an input 14, and the position signal on the occasion is stored as the position of the left edge A of the sample 7, on the basis of a signal outputted from the comparator 22. The above-described measurement is repeated at each prescribed temperature, the dimensions of the sample 7 at each temperature are calculated by the CPU 14, and a rate of thermal expansion can be calculated on the basis of the calculated dimensions.
MAEDA YUKIO
SAGARA HIROSHI
Next Patent: WIDE-BAND AIR FUEL RATIO SENSOR AND DETECTING DEVICE