| 摘要 |
PURPOSE:To set the reference outside diameter dimensions easily without using a ring gage by providing a reference base having the upper surface and the lower surface crossing the base line at right angles and a setting reference instrument. CONSTITUTION:In case the dimensions of an object 1 to be measured is taken absolutely, a contact shoe 22 of a displaying means 20 is abutted on the upper surface 42 in a state that the reference base 40 is engaged with the contact area 12 of a saddle type fixed base 10 and a preset switch 27 is used in this state to set so that a virtual circle prescribed by both guide faces 41 and the upper surface 42, namely, the outside diameter of a reference circle is displayed by a digital display part 24. Then, when the prescribed object 1 to be measured is similarly abutted on the contact area 12 of the saddle type fixed base 10, a spindle 23 is displaced along the base line P following a deviation of the outside diameter D of the object 1 to be measured from the reference circle and a displayed value of the digital display part 24 is abstracted from or added to a preset value in accordance with the displaced amount to take the absolute measurement. |
