Buecher Wuermer

Designation: G? 12a Standard Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Nonmetallic Materials1. ASTM CommiKee E44 intends to address these concerns by creaIng a standard on meeIng the ASTM G‐ Standard PracIce for. OperaIng Fluorescent. Engaged Expert Terry Candlish discusses ASTM G and G tests which are used to evaluate sunlight and moisture exposure. ASTM.

Author: Kazrajin Gusho
Country: Guyana
Language: English (Spanish)
Genre: Travel
Published (Last): 16 May 2006
Pages: 234
PDF File Size: 13.23 Mb
ePub File Size: 6.1 Mb
ISBN: 495-5-45780-851-6
Downloads: 39115
Price: Free* [*Free Regsitration Required]
Uploader: Matilar

Moisture takes its own toll on surfaces, and the combination of sunlight and moisture can amplify damage, costing millions of dollars of depreciation each year. It may be tempting to assume that shorter wavelengths, continuous exposure, high temperatures, and other variables can result in more intense acceleration.

See Appendix X1 for lamp application guidelines. A number in parentheses indicates the year of last reapproval. The lamps shown in this section are representative of their type. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. In xenon arc testing, different optical filters may be applied to shift testing conditions for daylight, window glass, or extended UV spectrum exposure.

Differences in lamp ast, or spectrum may cause signi? Last previous edition approved in as G — Our team 1g54-12 that florescent light has lower correlation to sunlight than xenon arc light; therefore, we generally recommend using the ASTM G fluorescent test to test for interior exposure i. NOTE 9—Typically, these devices control by black panel temperature only.

For instance, a slight shift in formula may produce twice as much resistance to weathering. Standards can be obtained from appropriate standard authorities.

  INTERSERVLET COMMUNICATION PDF

Therefore, these bulbs are useful for testing interior applications. Note that glass transmission characteristics will vary due to manufacturer, production lot, thickness, or other factors.

Due to time constraints, however, many producers employ gg154-12 G and G laboratory chamber tests for reliable exposure results in shorter time periods. Maintain these conditions throughout the exposure.

This practice is limited to the procedures for obtaining, measuring, and controlling conditions of exposure. The design of the experiment used to determine the speci? Manufacturers of equipment claiming conformance to this standard shall determine conformance to the spectral power distribution tables for all?

NOTE 3—Do not mix different types of lamps. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every?

Ast, International recommends that a comparable material of identified performance a control be exposed at the same time as y154-12 test specimen. Weatherometers used in the G and G tests approximate performance via intense exposure to the damaging elements in sunlight.

Test results can be expected to differ between exposures using? The UVA is used for these applications because the low end cut-on of this lamp is similar to that of direct sunlight which has been? If a radiometer is awtm, it shall comply with the requirements in Practice G To assure uniform exposure conditions,?

Ultimately, the most realistic way to test for weathering is to allow the product to degrade in real time, with outdoor testing panels. Typically, this is done at 2 nm increments.

ASTM Ga 非金属材料的萤光UV灯曝晒_百度文库

Current edition approved Dec. In these special cases, the use of UVA lamps is recommended since the glass or plastic will? The total irradiance in each wavelength bandpass is then summed and divided by the awtm In the ASTM G test, xenon arc lamps simulate full-spectrum sunlight within a controlled test chamber.

  ANNAMAYYA KEERTHANALU IN TELUGU PDF

Very low levels of silica in spray water can cause signi?

D The g154–12 glass? Test results can be expected to differ between exposures using devices with? We can work with you to ascertain the most cost-effective, accurate testing approach for your material. The manufacturer is responsible for determining conformance to Table 1.

After inspection, the test specimen shall be returned to the test chamber with its test surface in the same orientation as previously tested. SPDs for sunlight were measured in Phoenix, AZ at solar noon at the summer solstice with a clear sky, with the spectroradiometer on an equatorial follow-the-sum mount.

The particular testing application determines which lamp should be used. Whether your business is local or global, we can ensure your ast, meet quality, health, environmental, safety, and social accountability standards for virtually any market around the world. Up to 20 test samples are mounted in the QUV and subjected to a cycle of exposure to intense ultraviolet radiation followed by moisture exposure by condensation.

Accelerated Weathering (QUV) ASTM G154, ASTM D4329, ASTM D4587, ISO 4892

Cracking, peeling, de-glossing, oxidation, and tensile weakening are additional outcomes of v154-12 sometimes such deterioration can even occur through window glass. The more common may be identi? A number of exposure procedures are listed in an appendix; however, this practice does not specify the exposure conditions best suited for the material to be tested.

Cycle 5 has been used for roo? As shown in Fig.