1、DEUTSCHE NORM June 1995 Determining the optical distortion and refractive power of safety glazing material for road vehicles DIN 52305 ICs 43.040.60 Supersedes October 1989 edition. Descriptors: Safety glazing, road vehicles, optical distortion, refractive power. Bestimmung des Ablenkwinkels und des
2、 Brechwertes von Sicherheitsscheiben fr Fahrzeugverglasung In keeping with current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker. Published with the agreement of theBundesministerium fr Verkehr (Ger
3、man Federal Ministry of Transport). Foreword This standard has been prepared by Technical Committee Prfung von Sicherheitsglas fr Fahrzeug- Verglasung of the Normenausschu fr Materialprfung (Materials Testing Standards Committee). Amendments The following amendments have been made to the October 198
4、9 edition: a) Equations (2), (4) and (5) have been corrected. b) The standard has been editorially revised. Previous editions DIN DVM 2302 = DIN 52302: 1937-06; DIN 52305: 1960-02, 1989-10. Dimensions in mm 1 Scope This standard applies to flat or curved safety glazing used in road vehicles, especia
5、lly for windscreens. 2 Field of application This standard specifies methods of determining the optical (angular) deviation and refractive power of safety glazing materials; these parameters serve as a measure of the optical distortion of the glazing. In addition, the methods described here provide a
6、 quick overview of the optical properties of large areas of safety glazing. Alternative methods (the reflection and collimation telescope test methods) are described in the Explanatory notes. Continued on pages 2 to 9. Translation by DI N-Sprachendienst. In case of doubt, the German-language origina
7、l should be consulted as the authoritative text. No pari of this translation may be reproduced without the prior permission of Ref. No. DIN 52305 : 1995-0 DIN Deutsches Institut fr Normung e. V., Berlin. English price group 07 Sales No. 0107 01.98 Beuth Verlag GmbH, D-10772 Berlin, has the exclusive
8、 right of sale for German Standards (DIN-Normen). COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling ServicesPage 2 DIN 52305 : 1995-06 3 Concepts 3.1 Angle between the incident ray (here, normal to the glazing surface) and the emergent ray refracted by the gl
9、azing material. This angle (designated here bya,) is dependent on the wedge angle, y, which is the angle between the two surfaces of the material (cf. figure 1). Optical (angular) deviation (at an angle of incidence of O) Figure 1: Angular deviation,a, angle of incidence, E, and wedge angle, y 3.2 O
10、ptical (angular) deviation (at an angle of incidence other than O) Angle between the incident ray (here, at an angle of incidence, E, other than Oo) and the emergent ray refracted by the glazing material. It is dependent on the angle of incidence, wedge angle and any curvature in the material, and i
11、s designated by a designated by DE. 3.5 Relationship between quantities The following equation shows the relationship between the angular deviation, a 6.2.2 Screen and slide for determining refractive power (horizontal lines) The screen shall be flat and white. The slide shall be capable of producin
12、g horizontal lines (1 2 f 0,5) mm in width, thus forming a pattern of horizontal black and white stripes on the screen. Slides with horizontal lines shall be marked either with AZ DIN 52305 (method A) or BZ DIN 52305 (method B). 6.3 Support stand The support stand shall be capable of securely holdin
13、g the test material at the specified angle so that the specimen is not bent. 7 Specimens The specimens shall be the glazing material (e.g. windscreens) as delivered. 8 Procedure 8.1 For both test methods, the test arrangement shall be as in figure 5. When testing with a point light source (method B)
14、, the slide shall be placed between the light source and the specimen (cf. figure 6). Figure 7 shows the arrangement for test method A. The angular deviation of flat specimens shall be determined as follows. I, = 4m 12=4m t- - I Point liaht source or Droiector Specx-k- Y-Y- / Diaphragm E Figure 5: B
15、asic test arrangement 2, The SI unit is the radian (rad); 1 minute (1 ) = 290,888 . 1 O-6 rad. COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling ServicesPage 5 DIN 52305 : 1995-06 Point light source Slide 1 Diaphragm I 7 4m - Ern - Figure 6: Arrangement for t
16、est method B Lightsource Lens I I 1 Condenser Figure 7: Arrangement for test method A 8.2 figure 5). For both test methods, the specimen shall be placed 4 m from the screen at an angle equal to E (cf. 8.3 First, adjust the test image (slanted lines) projected through an optically clean piece of glaz
17、ing material with a consistent thickness (.e. with an angular deviation of Oo) so that each projected line falls in the exact centre of the space between the lines painted on the screen. The lateral displacement of the projected lines from the painted lines, V, in mm, is a function of the glazing ma
18、terial thickness and E, as shown in equation (3): i cos E V=s.sin 1- ln2 -sin2 y1 is the refractive index of the specimen material; E is the angle of incidence. NOTE: Where y1 = 1,5 and E = 55“, then V is 0,45 s. Before inserting the specimen, adjust the slide so that the lateral displacement of the
19、 projected lines is equal to the value calculated as described above. The distance between the projected lines can be adjusted by simply changing the distance between the projector and the screen. 8.4 Insert the specimen at an angle of 55“ in such a manner that the main direction of the distortion o
20、n the screen is horizontal. For best results, only the centre of the projected image should be examined for measure- ment purposes, while the surrounding area (which is to be about 60 mm wide unless otherwise specified) should be ignored. 8.5 highest value for this shift is to be measured with the a
21、id of the lines painted on the screen. If the specimen has a wedge angle, then the projected lines will be shifted from the central position. The 8.6 power as in subclause 8.7, with the following changes. For curved specimens, testing for angular deviation shall be as in subclauses 8.1 to 8.5 and fo
22、r refractive COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling ServicesPage 6 DIN 52305 : 1995-06 It should be noted that when testing curved specimens, the dimensions of the image area to be examined will depend on the curvature of the specimen 3. Although e
23、quation (4) allows for the estimated effect of the curvature on angular deviation, the image area should be limited so that the value for a r is the radius of curvature, in m; E is the angle of incidence; n is the refractive index of the specimen material. 8.7 To determine the refractive power of fl
24、at specimens, adjust the projected test image so that the horizontal lines are of the width specified in subclause 6.2.2. Then, insert the specimen and measure the change in width. Because the refractive power of the specimen material varies, the width of the projected horizontal lines will also var
25、y. Therefore, the highest and lowest values of the line widths are to be measured in order to accurately determine the refractive power of the specimen. The refractive power of curved specimens shall be determined as described above, taking the specifications of subclause 8.6 into consideration. 9 E
26、valuation 9.1 Angular deviation The angular deviation, ao, is to be expressed in minutes and calculated using equation (5). ao = 6(n - 1) f( n is the refractive index of the specimen material; 1, is the distance between the specimen and the display screen, in m; is the angle between the lines (proje
27、cted through optically clean material) and the horizontal plane (in figure 4, this angle is 30“). For f(e), see equation (1). 9.2 Refractive power The refractive power, Do, is to be expressed in dioptres and calculated using equation (6). Ab(Zl + Z2 ). (n - 1). cos E Do = b.Zl .Z2 .f() where b Ab 1,
28、 1, n For f(e), see equation (1). NOTE: For a change in width, b, of 1 mm and an incidence angle, E, of 55“, the refractive power will be is the width of the projected lines before the specimen was inserted, in mm; is the change in width of the projected lines after the specimen was inserted, in mm;
29、 is the distance between the projector (or light source) and the specimen, in m; is the distance between the specimen and the display screen, in m; is the refractive index of the specimen material. 0,Ol dioptres. 10 Test report The test report shall refer to this standard and include the following i
30、nformation: a) sampling method; b) type of glazing material tested; c) dimensions and shape of specimen (e.g. flat or curved); COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling ServicesPage 7 DIN 52305 : 1995-06 type of specimen; number of specimens; test met
31、hod used (cf. clause 5); angular deviation, ao, for each specimen, in minutes; refractive power, Do, for each specimen, in dioptres; for acceptance testing, the number of specimens that did not meet quality requirements. Standards and other documents referred to DIN 52335 Determination of the optica
32、l distortion of safety glazing for road vehicles DIN 52336 Determination of the secondary image separation of safety glazing for road vehicles ISO/DIS 35383) Road vehicles - Safety glazing materials - Test methods for optical properties ECE Regulation No. 43, Einheitliche Vorschriften fr die Genehmi
33、gung des Sicherheitsglases und der Verglasungswerkstoffe (Standard regulations for the approval of safety glazing and glazing material) Bibliography l Metzger, K. Beitrag zur optischen Prfung von Flachglas im reflektierenden Licht (Testing optical proper- ties of clear flat glass in reflecting light
34、), Glastechnische Berichte, 1957: 30, 296-299. 2 Kerkhof, F. Optische Wirkungen von Flachglas mit unebenen OberflSjchen (Optical properties of clear flat glass with uneven surfaces), Glastechnische Berichte, 1952: 25, 71-83. 3 Kerkhof, F. Zur optischen Prfung von Glasscheiben mit unebenen OberflSjch
35、en (Testing the optical prop- erties of glass with uneven surfaces), Glastechnische Berichte, 1957: 30, 369-379. 4 Schardin, H. ber die Prfung von Flachglas (Testing clear flat glass), Glastechnische Berichte, 1952: 25, 5 Egner, K. and F. Drr. Optische Prfung von Windschutzscheiben (Testing the opti
36、cal properties of windscreens), Automobiltech. Z., 1953: 55, 256-258. 6 Ramsauer, R. and A. Krings. Die optische Prfung von Sicherheitsglas fr Kraftfahrzeuge (Testing the optical properties of safety glazing for road vehicles), Automobiltech. Z-, 1955: 57, 335-338. 7 Kuske, A. Prfung von Windschutzs
37、cheiben auf Verzerrungen (Testing windscreens for optical distortion), Automobiltech. Z-, 1957: 59, 170-1 71. 8 Schardin, H. Glastechn. Interferenz und Schlierenaufnahmen (Interference testing and schlieren photog- raphy for glass), Glastechnische Berichte, 1954: 27, 1-1 2. 9 Schardin, H. Die Schlie
38、renverfahren und ihre Anwendungen (The schlieren method and its uses), Ergebnisse der exakten Naturwissenschaften, 1942: 20, 303-439. 69-70. Ex planat ory notes The determination of the optical distortion of safety glazing for road vehicles is also covered in ISO/DIS 3538, DIN 52335 and ECE Regulati
39、on No. 43. The optical properties of safety glazing for road vehicles are especially of importance when objects are to be viewed through the glazing (as is the case with windscreens). These properties are largely dependent on the wedge angle and refractive power of the material (2, 4) for the follow
40、ing reasons: The wedge angle deflects the light rays penetrating the material, causing the objects viewed through the windscreen to be laterally displaced, while the refractive power of the material distorts the viewed objects. The projection test methods The test methods specified here are based on
41、 the projection methods described in the works of K. Egner and F. Drr 5 and R. Ramsauer and A. Krings 6. These authors recommend the use of a projector with afocal length of 1 O cm and an aperture ratio of 1 : 2,5. Projectors with a focal length of 9 cm may be used with suitable slides. Such project
42、ors do produce a sharp raster image, but because the optical system of the light source is rather long, the central projection is blurred. For this reason, the refractive power can only be precisely determined by compensating with suitable lenses. And when determining the angular deviation according
43、 to Egner and Drr, it is difficult to establish the amount of error due to the extreme rake angle specified for the specimen (in Egner and Drr, 70“). These problems can be overcome by ensuring a central, sharp projection of the raster image 3; this is obtained using the two test arrangements specifi
44、ed in this standard. 3, Obtainable from Beuth Verlag GmbH, Burggrafenstrae 6, D-10787 Berlin. 4, Obtainable from DITR Deutsches Informationszentrum fr Technische Regeln im DIN, Burggrafen- Strae 6. D-10787 Berlin. COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Hand
45、ling ServicesPage 8 DIN 52305 : 1995-06 a) Test method A (figure 7) A low voltage point light source is supplied with a condenser and a lens. The size of the diaphragm aperture ensures the sharpness of the projection: The smaller the aperture, the smaller the specimen area will be through which a sh
46、arp image is possible. At the same time, smaller apertures have an adverse effect on the sharpness of the image, due to the curvature of the lens through which the image is projected. These two opposing effects can be compensated for by sacrificing an extremely sharp projection for a clear projectio
47、n of the raster image. The brightness of the projected image is equally of importance; this will depend on the diaphragm aperture and light source used. b) Test method B (figure 6) Here a point light source is used without other optical devices to project the image. If the area of the material to be
48、 examined is very small, the diaphragm aperture is likewise to be small. This also holds true for the slide (raster), which should be placed as close to the specimen as possible. The minimum aperture should be selected solely on the basis of the brightness of the light source and the required sharpn
49、ess of the projected image. It is easier to adjust the position of the slide with this test arrangement, and the heating effect of the projector is avoided. The test arrangement specified in this standard (.e. with the specimen centred between the projector/light source and display screen) produces the highest sensitivity for the largest possible examination area, as discussed in 8 (cf. figure 5). Kerkhof 3 reports that, with test method A, the raster image is blurred by about 1 mm and the smallest visible
