The present invention discloses a one-dimension position measurement system comprising: - a first ruler, on which is applied a first one-dimension code, - a second ruler, on which is applied a second one-dimension code, - a camera for acquiring simultaneously a picture of a portion of the first one-dimension code and of a portion of the second one-dimension code, and - some processing means. According to the invention, the second ruler is disposed parallel to the first ruler, one end of said first ruler being tied to one end of said second ruler, the other end of said first and second rulers being free. Moreover, said first and second rulers are made of material having different temperature expansion coefficients.