SAE J2019:1994 pdf free download.ACCELERATED EXPOSURE OF AUTOMOTIVE EXTERIOR MATERIALS USING A CONTROLLED IRRADIANCE AIR-COOLED XENON-ARC APPARATUS.
1. Scope
1.1 SAE J2019 sQecliies the operating procedures tat a controlled Irradiance. air-cooled xenon arc psratus used for the accelerated exposure 01 various automotive extenor malenats.
1.2 The sample preparation, test durations. and pertorma,e evaluation procedures are covered in material spelications of the different automotive mam,taurers.
2. Ral.renc.s
2.1 Applicable PubNc.tlons—The lollowg putllcateons lorm a part of this specification to the extent specltled herein. The latest issue of SAE publications shal apply.
2.1 1 SAE Pue.ecMiow—Available I rein SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.
SAE J1545—lnsinjmental Color Difference Measurement for Exterior Finishes. Textiles and Colored Titin
21.2 ASTM PuaicATS—Aveitable from ASTM. 1916 Race Street. Pheadeiphia, F 19103-1187.
ASTM G 26—Standard Practice for Operating Light Exposure Apparatus (Xenon Arc Type) With and Without Water for Exposure of Nonmetallic Mateñals
ASTU 0859—Test Methods for Silica m Water
ASTU 0 4517—Test Method for Low•L.evd Total Silica li High Purify Water by Ftameless Atomic Absorption Spectroscopy
2.1.3 CIE PusucArtori—Avallable from Commission International de Ledair age, 52 Bd Malesherbes. F.75006 Paris. France.
3. Definitions
3.1 Black Standard Thermometer, N—A temperature measuring device. whidt uses a resistance thermometer vein good heat-conchicting properties, titled to the reverse side of a metal plate. The metal plate is fixed to a plastic plate so that it is thermally .sulated It Is coated with a black layer,
3.2 Color Change, N—As used In fade-weathering testing, a change In color ad any kio (whether a change In hue, saturatin, or Ightnessl.
3.3 Irradlance, N (E)—The men( radiant flux per unit area of a suitace (W1m2.
3.4 Irradlance, Controlled. N—The maintenance by closed loop teediack of a preselected irradiance throughout a designated exposure interval
3.5 Irradlarice, Spectral, N—The radiant enorgy within a specified wavelength interval that falls on a unit area of exposed surface (W1m2/nm).
3.6 lrraddance, Total. N—Radiant energy integrated over all wavelengths talang on a unit area of exposure at a poInt In tim. expressed Wi watts par square mete (WImt)
3.? IrradIatIon, N—See radiant exposure.
3.8 Long-arc Xenon, N—A xenon arc in which the length of the arc between electrodes as greater than the diameter of the envelope enclosing the arc-
3.9 RadIant Exposure. N—The time Entepral of irradiance (J/m2).
3.10 Radiant Exposure, Spectral, N—The inleation of spectral irradiance with respect to time (J/m2.nm).
3.11 Reference Plastic. N—A clear polystyrene plastic standard selected for exposur, as a check on a lest apparatus and operating conditions.
3.12 Sample, Laboratoa’y, N—A portion of material taken to represent the lot sample or the original materiaL and used in the laboratory as a source of test apecimens
3.13 SpecImen. N—A specific portion of a material or a laboratory sample on wtWch a test is perlormed or that is selected for that purpose.
3.14 Spectral Power Distribution, N—The varration of energy due Ia the source over the wavelength span of emitted radlation
3.15 Wavelength Range, N—The specilied wavelength range for bandpass fliers; for example. 300 to 400 nm.
4. SIgnificanc, and Us.—This test method is designed to simulate extreme envtronmental condlitions encounlered oulside a vehicle such as sunlight, heat, and moisture (in the form of humidity, condensation, or rain) for the purpose 0* prechcllng the weatherabilily of automotive materials,
5. Equipment—A more complete description of the apparatuses listed as follows may be found in ASTM G 26.
5.1 Air-Cooled Type1
The apparatus employed shall use an air-cooled xenon-arc lamp as the source of radiation and should be as follows:
5.1.1 GENERAL—An apparatus using three lamps based on xenon-arc technology that meets the conditions specified in Section 6 is acceptable as long as the filter/optical systems reproduce the spectral distribution of the lamp output and filter system specified in this document. Also, all temperature and humidity must be identical to the conditions specified in Section 6.
5.1.1.1 Spectral Power Distribution—The spectral distribution shown in Table 1 (based on CIE Publication No. 85 (1989) Table 4) specifies acceptable ranges within wavebands to describe the lamp output defined in this standard.
5. 1.1.2 Specimen holders shall revolve around the arc, with the sample plane describing a spherical or cylindrical surface. A slight tilting of the upper and lower sample holders can provide uniformity satisfactory to eliminate the need to reposition specimens in the sample rack and allows use of the complete sample holder.
5.1.1.3 Testing temperatures shall be calibrated using a Black Standard Thermometer unit that is mounted so that the face of the unit is subjected to the same influences as the test specimens.
5. 1.1.4 A blower unit in the base of the apparatus shall provide a flow of air through the test chamber and over the test specimens. Control of the specimen, test chamber, and the black standard temperature shall be accomplished by thermostatic control of the chamber temperature and adjustment of the air flow rate to obtain the specified black standard temperature.
5.1.1.5 Relative humidity in the test chamber shall be measured and controlled by a hygrometer. Water should be vaporized and diffused to enrich the air with moisture and produce the required humidity.
6.1 To insure repeatability of tests, maintain and calibrate the apparatus to manufacturer’s specifications, and as described in Appendices A and B. Appendix A contains additional maintenance instructions and replacement schedules and Appendix B describes the use of reference plastic to determine if the xenon-arc apparatus is operating within the desired range.
6.1.1 The input voltage must be between 200 to 240, 340 to 420, or 400 to 440 V based on manufacturer’s specifications.
6.1.2 Water used for the specimen spray and humidification system shall leave no objectionable deposits or stains on the exposed specimens. It is strongly recommended that the water contains a maximum of 1 ppm solids and a maximum of 0.2 ppm silica. Silica levels should be determined using ASTM 0 859 or ASTM D 4517. A combination of deionization and reverse osmosis treatment can effectively produce water with the desired purity.
6.1.3 Install both front panel and sample cooling (back side of specimen) spray nozzles.
6.1.4 Install three sections of Suprax filter system, or equivalent to match 5.1.1.1.
6.1.5 Program the microprocessor for the test conditions in Table 2. Program other functions to be OFF.
7. Test Procedure
7.1 Prepare the specimens to be exposed to fit the specimen holder being used.
7.2 Specimen sizes must conform to the size of the specimen holder(s) supplied by the manufacturer for use with the equipment. Specimens that exceed these sizes may not give proper exposure results. Instructions for mounting parts or portions of a part can be obtained from the automotive company for which the material is being tested.
7.3 Insert specimen in holder and secure. Under no circumstances should the face side of the sample be closer to the arc than the front side of the specimen holder.
7.4 Fill all unused slots in specimen holders with unpolished stainless steel blanks to maintain desired air flow.
7.5 Expose specimens, beginning with the dark cycle, for the required radiant exposure (Megajoules per square meter [MJ/m2J) measured in the wavelength range of 300 to 400 nm. See applicable material specification.
7.6 Report the degree of fade or other changes as outlined in SAE Ji 545.
7.7 Exposure Report
7.7.1 A copy of the exposure report, Figure 1, must be included with each exposed specimen being submitted for aDDroval.