1、c al al m - L m E O z L - c a = c imm Scale interval UP to 50 Irmh or 10“ Arrangement of working surface I I Scale interval up to 50 pm/m or 10“ Scale interval over 50 pm/m or lor for IjlOmm I 1100mm Horizontal Vertical Table 3. Limits of error for the aro of electronic inclination measuring systems
2、 conforming to DIN 2276 Part 2 5 ymlm 0,4 scale division 0,2 scale division 10 pmlm 1 xale division 0,5 scale division 4.1 Geometrical toleranr 4.1.1 Working suriaces The values given in table 1 shall apply for the flatness tolerance, tg, indicated in figure 1, as well as, where applicable, for the
3、tolerance on parallelism between the second (upper) horizontal working surface and the lower horizontal working surface. 4.1.2 Side faces The following formula shall apply for the common tolerance of the side faces: 1 t=100+- 10 and the following formula shall apply for the squareness tolerance of t
4、he side faces to the working surfaces: b t=100+- 2 where t is the respective tolerance value, in prn; I is the numerical value of the length in mm; and b is the numerical value of the width in mm. The side faces may be enamelled. 4.2 Cross-level The provision of a cross-level is required in the case
5、 of inclination measuring instruments which have working surfaces corresponding to type A and scale intervals on the main inclination measuring system up to 300 m/m or 60“. 4.3 Zeroerror The limit values specified in tables 2 and 3 apply for the zero error. In the case of digital indication, the val
6、ues obtained shall be rounded to whole numerical intervals. In addition, drift and temperature coefficient as specified in DIN 2276 Part 2 shall be taken into consideration. Note. Where more stringent requirementsare to be met, it is advisable that the inclination measuring system be provided with a
7、n adjustment facility. A limit of error of 2 mm/m shall apply for the zero position of the cross-level. 4.4 Lateral stability Given a lateral inclination of 10“ starting from the zero position of lateral inclination, an error of indication of the DIN 877 Page 3 main inclination measuring system is p
8、ermitted up to one scale interval or 20 wm/m (whichever is the greater). Note. Where inclination is measured with systems having scale intervals of up to 20 m/m, care shall be taken to restrict as far as possible any changes in lateral inclination. 4.5 Error of indication For indications other than
9、zero, the limit of error shall be obtained by combining the relevant value given in table 2 or table3 with the limit of error specified for the inclination measuring system in either DIN 2276 Part 1 or Part 2. 4.6 Working temperature range The requirements specified in subclause 4.3 shall be met at
10、the working temperature of (20 I5) OC. 4.7 Thermal protection The inclination measuring instrument and any inclination measuring system mounted in it having a scale interval of up to 100 pm/m or 20“ shall be protected against the adverse effects of acute fluctuations in temperature. 5 Testing Testin
11、g shall be carried out with the instrument posi- tioned as in actual use, or with the cross-level settled at zero. Both the flat working surfaces and the V grooves shall be tested. 51 Zero position of horizontal working surfaces The test shall be carried out “in transit“ around the vertical axis pas
12、sing through the middle of the inclina- tion measuring instrument. The result of the test is the arithmetical mean of the two readings, due allowance being made for their signs or directions as defined by the inclination measuring instrument. A grade 00 surface plate conforming to DIN 876 Part 1 or
13、Part 2, positioned so as to be as level as possible, shall be taken as the datum base for inclination measuring instruments with scale intervals up to 1 O0 bm/m or 20“, while for inclination measuring instruments with scale intervals over 100 wm/m or ZO“, a grade O surface plate conforming to DIN 87
14、6 Part 1 or Part 2 shall be used. For testing the V grooves, a test cylinder shall be used which is so dimensioned in respect of its diameter that it contacts the working surfaces at any point except for the edges, which is longer than the inclination measuring instrument, and satisfies the followin
15、g requirements as specified in DIN 2272 Part 1 : for scale intervals up to 100 pm/m or 20“: for scale intervals over 100 pm/m or 20“: requirement DIN 2272 - GO - KO - POO, and requirement DIN 2272 - G1 - K1 - Poo. 5.2 Zero position of vertical working surfaces As far as flat working surfaces are con
16、cerned, testing shall be carried out in transit around a rigid clamping block, the working surfaces of which shall be as nearly vertical as possible and satisfy the requirement DIN 2272 - E - P - OO. In the case of V grooves, the test cylinder specified in subclause 5.1 shall be used vertically. The
17、 other specifications of subclause 5.1 shall apply here analogously. 5.3 Error of indication The error of indications other than zero may be checked using a DIN 2273 sine bar or another suitable measuring set-up. In cases of arbitration, however, the use of a DIN 2273 sine bar is required. 6 Materia
18、l The working surfaces of the inclination measuring instru- ments shall be made of a wear-resistant material. Unless otherwise agreed, the choice of material shall be the responsibility of the manufacturer. 7 Marking The scale interval, together with the unit, of the main inclination measuring syste
19、m shall be marked on the inclination measuring instrument using the following symbol as specified in DIN 2258. it- Page4 DINS77 Standards referred to DIN 876 Part 1 DIN 876Part2 DIN 1319 Part 1 DIN 1319 Part 2 DIN 1319 Part 3 DIN 2257 Part 1 DIN 2258 DIN 2272 Part 1 DIN 2273 DIN 2276 Part 1 DIN 2276
20、 Part 2 Surface plates; granite surfaces plates; requirements, testing Surface plates; cast iron surface plates; requirements, testing Basic concepts in metrology; general basic concepts Basic concepts in metrology; terminology relating to the use of measuring instruments Basic concepts in metrology
21、; terminology relating to the uncertainty of measurement and the assessment of measuring instruments and measuring equipment Terminology used in dimensional metrology; units, activities, checking instruments, metrological concepts Graphical symbols used in dimensional metrology Requirements to be me
22、t by inspection equipment in dimensional metrology; auxiliary equipment Sine bars Inclination measuring systems; cylindrical spirit level vials; dimensions and requirements Inclination measuring systems; electronic inclination measuring systems; types and requirements Previous editions DIN 877: 10.3
23、2,05.59. Amendments The following amendments have been made in comparison with the May 1959 edition of this standard: a) classification into instrument classes has been dispensed with; b) requirements have been specified solely with regard to the zero position; c) the standard designation has been introduced; d) marking has been introduced; e) the text has been editorially revised. International Patent Classif ication G O1 C 9/00
