| 摘要 |
PURPOSE:To easily generate atmospheric pressure (reference pressure) and calibration pressure by moving a piston within a cylinder. CONSTITUTION:A piston 2 moves within a cylinder provided with an opening part 3 opened to the atmosphere. The initial position of the piston 2 is on the side left- ward from the part 3 and in this state the pressure in the cylinder 1 is atmosphere pressure through the part 3. Next, when the piston 2 is moved past the part 3 and when the leading end of the piston 2 passes the point P of the part 3, the part 3 is closed by the piston 2, and the pressure in the cylinder 1 is shut off from the atmospheric pressure. The pressure in the cylinder 1 is determined by the distance at which the leading end of the piston 2 moved from said point P. The rise in the pressure in the cylinder 1 is detected by a converter 7, and the pressure is calibrated. In the case of pressure calibration, a changeover valve 5 is closed of the side (a) and is communicated of levers b-c. |
