ASME B89.1.10M pdf download

ASME B89.1.10M pdf download DIAL INDICATORS (FOR LINEAR MEASUREMENTS)
8 GENERAL REQUIREMENTS
8.1 Materials
8.1.1 Bearings. All types ofindicators are furnished with either plain or jeweled bearings, or a combination of both.
8.1.2 Case. Dial indicator cases shall be of such strength and rigidity as to ensure free movement of the mechanism under normal shop condition.
8.1.3 Contact Points. Contact points shall be of hardened steel or other wear-resistant material with smooth uniform gaging surfaces. Except for Type A, Group 0, and Type C dial test indicators, all points shall have a #4–48 thread.
8.1.4 Crystals. The crystals shall be clear and preferably of nonshattering material.
8.2 Construction
8.2.1 Position. The zero position of the dials shall be adjustable over a range of 360 deg and the desired position fixed by a locking device or held by friction means between the case and bezel.
8.2.2 Dial Hands. The width of the tip shall be approximately the same as that of a graduation line on the dial face. Type A, 2 1 ⁄ 2 -revolution indicators, shall have their hands set at approximately the nine o’clock position when the spindle is fully extended. One-revolution indicators shall have their hands set at approximately the six o’clock position at the bottom of the indicator dial. Type B indicators shall have their hands set in accordance with individual manufacturer’s practice.
Type C indicators will have their hands set at either the six o’clock or twelve o’clock position with the lever at rest.
8.2.3 Dial Indicator Range. For Type A indicators, the minimum range shall be 2 1 ⁄ 2 revolutions of the indicating hand unless specifically intended for use as a one-revolution indicator or unless specified for applications requiring shorter or greater travel. Types B and C shall have a minimum range of one revolution of the dial hand. Dial indicators with longer than specified range are referenced in para. 8.4.
8.2.4 Physical Dimensions. Refer to Fig. 1 for standard dimensions of Type A dial indicators. Types B and C (Figs. 2 and 3) are illustrated for general appearance. The individual manufacturer’s standard practice should be consulted. Table 1 shows size group limits for nominal bezel diameters and corresponding minimum position distances along the spindle axis between contact point and center of dial for Type A indicators.
8.2.5 Dial Faces. The dial faces shall have sharp, distinct graduations and figures. Metric dials shall be yellow. One-revolution dial indicators may have a dead zone at the bottom of the dial face indicating an out- of-range condition. The dead zone may occupy no more than 20% of the circumference of the indicator. There shall be no graduations or numbering within the area occupied by the dead zone. 8.2.6 Dial Markings. Dial markings shall indicate the value of the least graduation, either inch or millime- ter, and shall be in decimals [i.e. 0.001 in., not 1 ⁄ 1000 in.; or 0.01 mm, not 1 ⁄ 100 mm (Fig. 6)].