ASTM D904-99 (R2021) pdf free download.Standard Practice for Exposure of Adhesive Specimens to Artificial Light.
1 .1 This practice covers the basic principles and operating procedures for ultraviolet (UV) light aging (with or without water) of adhesive bonded joints having at least one glass or transparent adherend. using fluorescent UV (see Method A) or xenon-arc light sources (see Method B).
1 .2 This practice is limited to the apparatus for obtaining, measuring, and controlling the aging conditions, and to the procedures for exposure. Sample preparation, strength. test conditions, and evaluation of the results arc described in other ASTM test methods or specifications.
1.3 The values stated in SI units arc to be regarded as standard. No other units of measurement are included in this standard.
3. Terminology
3.1 Definitions—Many of the terms in this practice are defined in Terminology D907.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 irradiance, n—(1) the rate at which light energy falls on a unit area of surface (W/nr), or (2) the radiant power incident upon a unit area of surface.
3.2.2 radiant exposure (or light dosage), n—(1) the accumulated light energy which has fallen on a unit area over time (J/m2). or (2) the irradiance integrated with respect to time.
3.2.3 spectral irradiance, n—the distribution of irradiance in accordance with wavelength.
3.2.3.1 Discussion—Spectral irradiance is usually shown as a curve relating irradiance (ordinate) and light wavelength (abscissa). Because shorter wavelength UV is usually more damaging than longer wavelength UV, lamps with different spectral irradiance curves can cause drastically different amounts of UV damage, even if they produce the same total irradiance.
3.2.4 spectral power distribution (SPD), u—the amount of radiation present at each wavelength.
3.2.4.1 Discussion—The SPD can be expressed by power in watts, irradiance in watts/square metre, or energy in joules. The shape of the SPD would be identical in all of these units. Fluorescent lamps are frequently described by relative SPD’s which show the amount of radiation at each wavelength as a percentage of the amount of radiation at the peak wavelength.
3.2.5 UV-A, n—ultraviolet light in the wavelength band between 315 and 400 nm.
3.2.6 UV-B, n—ultraviolet light in the wavelength band between 280 and 315 nrn.
4. Significance and Use
4.1 This practice is for determining the effects of UV light, or UV light and water, on adhesive bonded joints under controlled but artificial conditions. The results of this practice can be used for comparing the relative durability of several adhesives in a specific laboratory UV exposure.ASTM D904 pdf download.