| 摘要 |
PURPOSE: A digital extensometer is provided to measure height length accurately, by including three hall sensors and a magnetic scale. CONSTITUTION: A magnetic scale (32) forms magnetic scale. Sliding grooves (66,66') are formed longitudinally in a vertical frame (30). A movement measurement instrument measures the displacement as moving along the length direction of the magnetic scale. A first and a second hall sensor output a signal for the moved displacement and the movement direction. A third hall sensor measures reference displacement. |
