| 摘要 |
The object of this invention is to provide a method for improving the accuracy of measurements, distance measurements in particular, made with a laser interferometer consisting of an interferometer (1) and a retroreflector (2). In the method according to this invention, simultaneously with the normal distance measurement made by the laser interferometer (1), the speed of sound (5) is also measured over the same distance travelled by the laser beam (3). The value of the speed of sound is calculated utilizing the distance obtained by the laser interferomter between the interferometer (1) and the retroreflector (2). Utilizing the observation, that the speed of sound and the laser beam wavelength depend on the same air properties or factors, and the quantities in question have a known comparability with each other, a correction, which depends on the variable properties of air, based on the speed of sound value, is calculated to the laser interferometer's original measured value, and especially distance measurement. The laser interferometer's measuring accuracy is substantially improved when so corrected. |
