1、DEUTSCHE NORM June 199! I I Precision dial indicators Part 1 : Analogue indicators DIN 879-1 - ICs 17.040.30 Prfen geometrischer Gren - Feinzeiger - Teil 1 : Mit mechanischer Anzeige Supersedes October 1983 edition. In keeping with current practice in standards published by the International Organiz
2、ation for Standardization (ISO), a comma has been used throughout as the decimal marker. Foreword This standard has been prepared by Technical Committee Eindimensionale iangenprftechnik of the Normenausschu Technische Grundlagen (Fundamentals in Technology Standards Committee). Amendments This stand
3、ard differs from the October 1983 edition as follows. a) Statistical concepts have been harmonized with the International Vocabulary of Metrology l b) New illustrations have been included in figures 1 and 2, and figure 3 has been deleted. c) The standard has been editorially revised. Previous editio
4、ns DIN 879: 1943-1 O, 1970-06; DIN 879-1 : 1959-05, 1979-01, 1983-1 O; DIN 879-2: 1961 -04. All dimensions are in mm. 1 Scope This standard specifies requirements for and the verification of precision dial indicators with analogue indication (without electrical limit contacts) and having scale inter
5、vals of 0,5 pm, 1 pm, 2 pm, 5 pm, 1 O pm, and 50 pm, and a measuring span of 0,05 mm, 0,l mm, 0,2 mm, 0,26 mm, 0,5 mm, 1 mm, and 3 mm. This standard does not cover waterproof or watertight dial indicators, which are subject to special require- ments. 2 Normative references This standard incorporates
6、, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text, and the titles of the publications are listed below. For dated references, subsequent amendments to or revisions of any of these publications apply to this
7、 standard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication referred to applies. DIN 102 DIN 1319-1 DIN 1319-2 Reference temperatures for measuring instruments and workpieces Basic concepts in metrology - General concepts Basic conce
8、pts in metrology -Terminology relating to the use of measuring instruments Continued on pages 2 to 5. Translation by DIN-Sprachendienst. In case of doubt, the German-language original should be consulted as the authoritative text. No pari of this translation may be reproduced without the prior permi
9、ssion of Ref. No. DIN 879-1 : 1999-0 hl Deutsches Institut fr Normung e. V., Berlin. Luth Verlag GmbH, D-10772 Berlin, hac the exclusive right of sale for German Standards (DIN-Normen). English price group 07 Sales No. 0107 04.00 Page 2 DIN 879-1 : 1999-06 DIN 2257-1 Terminology used in dimensional
10、metrology - Units, activities, checking instruments - Metrological concepts IS0 2768-1 : 1989 General tolerances - Part 1 : Tolerances for linear and angular dimensions without indi- vidual tolerance indications l International Vocabulary of Basic and General Terms in Metrology (VIM) = International
11、es Wrterbuch der Metrologie. 2nd GermadEnglish ed. Edited by DIN Deutsches Institut fr Normung e.V., 1994. I) 3 Concepts For the purposes of this standard, the concepts defined in DIN 1319-1, DIN 1319-2, DIN 2257-1 and l apply, as well as the following concepts. 3.1 Precision dial indicator An indic
12、ating measuring instrument in which the displacement of the plunger is mechanically transmitted to a pointer moving in front of a part circular scale extending over an arc of less than 360“ and graduated in equal divisions. 3.2 Error of indication Indication of a measuring instrument minus a true va
13、lue of the corresponding input quantity l. 3.3 Limits of permissible error Extreme values of an error permitted by this standard l. Designated by G (cf. figure 2). 3.4 Repeatability Ability of the dial indicator to provide closely similar indications for repeated measurements of the same measurand u
14、nder the same conditions of measurement l. 3.5 Repeatability limit Extreme values specified in this standard characterizing the dispersion of results forthe same measurand under repeatability conditions, within the measuring span and with the plunger moving in the same direction. Desig- nated by r.
15、4 Dimensions and designation 4.1 Dimensions The designs shown are for illustrative purposes only; however, the dimensions of indicators shall be as speci- fied. General tolerances shall be class m tolerances as in IS0 2768-1. Holes to receive the stem shall have a diameter of 8 mm and shall be manuf
16、actured to tolerance class H7. The preferred plunger diameter is 4 mm. 4.2 Designation Designation of a dial indicator with 5 pm scale intervals (5): Dial indicator DIN 879 - 5 5 Requirements 5.1 General For indicators with scale intervals greaterthan 1 pm, the values in table 1 shall be complied wi
17、th in any indicator position and shall not be exceeded at any point within the measuring range. For indicators with scale intervals of 1 pm or smaller, the specified limits of error, G, and hysteresis error, tu, apply for the vertical position with the plunger pointing downwards; in other positions,
18、 these values may be exceeded by 30 %. 5.2 Reference temperature The reference temperature shall be 20 “C, in accordance with DIN 102 I) Obtainable from Beuth Verlag GmbH, Burggrafenstrae 6, 10787 Berlin, Germany. Page 3 DIN 879-1 : 1999-06 Limit of hysteresis error, tu 1 Case 2 Pointer 3 Adjustable
19、 tolerance marks 4 Scale 5 Stem 6 Plunger 7 Measuring insert 8 Fine adjustment screw up to 1 pm over 1 pm 0,s 03 , 9max. 1 0,7 Limit of error in one direction of movement (retracting plunger) over a range of any ten scale divisions, Gti) Limit of error in one direction of movement (retracting plunge
20、r) over the entire measuring range, Gei) 1 Measuring insert 04min. 0,7 1 Detail x (shown in section without insert) 04 Figure 1 : Dial indicator dimensions and tolerances Table 1 : Characteristics of dial indicators Characteristic Permissible errors, in scale intervals For intervals I For intervals
21、Repeatability limit, r I 0,s I 03 Limit of error in both directions of movement (retracting and extending plunger) over the entire measuring range, GEesi) I lI2 I 1) The limits of error shall be met at any randomly selected setting within the measuring range. Any doubling of permissible errors is pr
22、ecluded because these values apply for any setting, including those at an extreme value. Page 4 DIN 879-1 : 1999-06 5.3 Measuring force and hysteresis error of measuring force The measuring force shall be no lower than 0,3 N and no greater than 1,5 N at any indicator position. Within the measuring r
23、ange, the difference between the minimum force and maximum force, in the same direction of movement as the plunger, shall be no greater than 0,4 N. The hysteresis error of the measuring force, shall not exceed 0,5 N at any setting within the measuring range. 5.4 Scale 5.4.1 Design Scale marks shall
24、be cleanly cut and in sharp contrast with their background. They shall be straight, equally thick, and centrally arranged facing towards the pointers axis of rotation. Major marks shall be longer than minor ones. Scale marks shall be spaced at least 1 mm apart, measured along the arc described by th
25、e tip of the pointer. The mark thickness should be 1 O YO of this spacing. Single values for the mark thickness shall not deviate from the mean by more than I0,02 times the spacing. 5.4.2 Scale intervals The scale interval shall be indicated by the numerical value and the unit, using the following s
26、ymbol, e.g. +I I+ 1 pm. 5.5 Pointer The pointer width shall be equal to the scale mark thickness (within the scale range) and its tip shall reach to two-thirds the length of the shortest mark. The pointer shall move clockwise when the plunger is being re- tracted. 5.6 Fine adjustment screw It shall
27、be possible to adjust the indication by at least ten scale intervals using the fine adjustment screw. 5.7 Movement of pointer and plunger The pointer shall have a pretravel and overtravel each of at least two scale intervals exceeding the measuring range. The plunger shall have an overtravel of at l
28、east 1 mm. 5.8 Measuring insert The measuring insert shall be interchangeable, wear-resistant and have a spherical measuring face with a radius of at least 1,5 mm, and the surface roughness parameter R, shall be no greater than 0,63 pm. 6 Verification 6.1 General It is recommended that, for verifica
29、tion purposes, the pointer be set to coincide with a scale mark and then any deviation of the plunger position read off from the verifying instrument; this is a more accurate procedure than trying to establish any deviations by reading off the dial indicator itself. The dial indicator should be veri
30、fied in a vertical position with the plunger pointing downwards. 6.2 Error of indication and hysteresis error The error of indication and hysteresis error shall be determined by taking readings at intervals of ten scale divisions (cf. figure 2). 6.3 Repeatability Repeatability shall be determined at
31、 any random setting within the measuring range. At least five measurements shall be performed. The greatest difference between readings shall be established and compared with the repeatability limits specified in table 1. 6.4 Measuring force and hysteresis error of measuring force The measuring forc
32、e and its hysteresis error should be verified in the middle and at both extremes of the measuring range. Page 5 DIN 879-1 : 1999-06 -0 -0.1 C .- -0.2 Lc o -0.3 2 -0.4 L I O X - Maximum error - / of indication - X - Skt 1 / L it I l / I Limit of error Ge Limit of error Gges -0.8 Limit of error Gges L
33、imit of error G, - -1.1 1 -1.2 I- 50 40 30 20 10 O 10 20 30 Skt SO Indication - O Retracting plunger X Extending plunger Figure 2: Plotting errors of indication 6.5 Apparatus The error of indication and hysteresis error may be determined using special verification equipment, microm- eters, comparato
34、rs, or indicator blocks. The measuring force shall be determined using a load cell or spring balance. NOTE: It is very difficult to determine the hysteresis error using indicator blocks. 7 Marking Dial indicators shall be permanently marked with the manufacturers name or trademark. Appendix A Inform
35、ation on use Care shall be taken that the plunger does not become jammed when the stem is clamped. The plunger shall neither be oiled nor greased, since this would adversely affect the instruments repeatability and hysteresis error. If the dial indicator is used in a position other than a vertical p
36、osition with the plunger pointing downwards, it shall be verified in this position as well. Indicators should be checked for wear or defects periodically (the intervals between checks will depend on the frequency and conditions of use). The shape of the measuring insert should be selected to suit th
37、e surface being measured. For instance, a flat surface is normally measured using an insert with a spherical measuring face. The concentricity of shafts should be measured using a blade-type insert or one with a transverse cylinder. Other relevant standards DIN 878 Dial indicators DIN 2270 Dial indicators (lever type)
