The AATCC TM16 Aging Test Method provides general principles and procedures commonly used to determine the color fastness of textile raw materials. This test is applicable to all kinds of textile raw materials as well as colorants, finishing agents and finishing agents to be applied to textile raw materials.
Significance and scope
1-1 The AATCC TM16 test method provides general principles and procedures commonly used to determine the color fastness of textile raw materials. This test is applicable to all kinds of textile raw materials as well as colorants, finishing agents and finishing agents to be applied to textile raw materials.

Test items include:

1- Carbon arc lamp, continuous illumination

2- Carbon arc lamp, alternating illumination and darkness

3- xenon arc lamp, continuous illumination, black panel choice

4- xenon arc lamp, alternating illumination and darkness

5-xenon arc lamp, continuous irradiation (standard blackboard thermometer)

6- Glass filter

1-2 The application of these test items applies to a specific device and does not imply special testing or rapid testing in other respects. The degree of correlation between the sun exposure test and the actual sun exposure shall be determined by accurate mathematics and recognized by both parties.

1-3 The test method contains the following parts, which are helpful for the application and execution of the various test items of textile raw materials.

AATCC TM16-0 “Aging Test Method”

2 Principles
2.1 The textile sample to be tested and the agreed comparison standard are simultaneously exposed to the light source of the specific environment. The color fastness of the sample was determined by comparing the color difference between the exposed part and the unexposed part, or by using AATCC gray sample card to compare with the original sample, or by means of color measurement by instrument. The insolation grade was determined by comparing the lightfastness of a set of AATCC blue wool exposed at the same time.

3 Terminology
3.1 AATCC Standard for Light Fastness to Blue wool: A set of dyed wool fabrics distributed by AATCC for measuring the color fastness of samples in sun testing (see 32.1)

3.2 AATCC Fading Unit (AFU) : a specific amount of exposure under the test conditions required by various test methods, where one AFU is equivalent to 1/20 of the L4 blue wool gray card of AATCC to level 4.

3.3 Blackboard thermometer: A temperature measuring device with a surface covered by black paint that absorbs most of the radiant energy in the exposure. (see 32.2)

3.3.1 This device provides the maximum temperature that the sample can reach in natural or artificial exposure, with 32. Any bias described in 2 May affect the measured temperature.

3.4 Black standard thermometer: a temperature measuring device with a surface covered with black paint that absorbs most of the radiant energy from the exposure and thermally insulated by a plastic sheet (see 32.2)

3.4.1 This device provides the maximum temperature that the sample can reach in natural or artificial exposure, with 32. Any bias described in 2 May affect the measured temperature. A black standard thermometer does not measure the same temperature as a blackboard thermometer, so the two cannot be used interchangeably.

3.5 Wide wavelength radiometer: relative term applied to radiometers with a wavelength width greater than 20nm at 50% of the maximum conversion rate. It can be used to measure the radiation energy at wavelengths like 300-400nm or 300-800nm.

3.6 Color difference: Used in color fastness testing, it is used to indicate the color difference in color fastness, hue, chromaticity or combination, obtained by comparing samples with unexposed samples.

3.7 Color fastness: the change or staining of the color properties of the material, or the color difference under any possible conditions of operation, detection, storage and use.

3.8 Sun fastness: the change in the color properties of the material caused by exposure to sunlight or artificial light sources

AATCC TM16-0 “Aging Test Method”

3.9 Infrared radiation: the wavelength of a monochromatic component is higher than that of visible light and less than 1mm of radiation energy.

Note: There is no precise definition of the spectral range limit of infrared radiation, different users have different definitions. The CIE E-2.1.2 association distinguishes it from 780nm to 1mm

IR-A: 780-1400nm

IR-B: 1.4-3.0µm

IR-C: 3µm-1mm

3.10: Radiant energy: Radiant energy per unit area, usually reported in watts per square meter

3.11: “L” standard solid: Determine the sequence of each blue wool standard based on the number required for each AATCC fading unit to produce a change equivalent to the AATCC Level 4 gray card.

Note: See Table 2 for the mathematical relationship between L standard and color fastness calculated in AFU. The color difference of the sample after exposure can be determined by comparing it with the nearest AATCC blue wool standard.

3.12 Langley: A unit of total solar radiant energy equivalent to one kilocalorie per square centimeter.

Note: international unit: joule: unit of radiant energy; A unit of radiated power; Square meter: unit of area. The following equation is often used: 1 Langley is equal to 1 card per square centimeter is equal to 4.184 joules per square centimeter, is equal to 41840 joules per square meter.

3.13 Color fastness: A property of a material indicating the nature of its color difference when exposed to sunlight or artificial light

3.14 Narrow band radiometer: A radiometer at 50% of the maximum conversion rate or with a band width of 20nm, which can be used to measure radiation energy at 340nm or 420nm wavelengths.

3.15 Photoreactive discoloration: The quality standard of any type of color difference, which can be immediately observed when comparing exposed and unexposed samples.

AATCC TM16-0 “Aging Test Method”

Note: The recovery of chromatic aberration in the dark and the stability of hue and chromaticity distinguish photoreactive discoloration from fading.

3.16 Heliometer: A radiometer that measures global or hemisphereal irradiance.

3.17 Radiated power: the amount of energy radiated per unit time

3.18 Radiometer: An instrument for measuring radiated power

3.19 Total radiant energy: the total radiant energy of a home at a point for all wavelengths, expressed in watts per square meter.

3.20 UV radiation: the radiation energy of a monochromatic component with a wavelength less than that of visible light but greater than 100nm

Note: The spectral range limits of UV radiation are not clearly defined and are understood differently by different users. CIE’s E.2.1.2 association defines 400 and 100nm.

UV-A 315-400nm

UV-B 280-315nm

UV-C 100-280nm

3.21 Visible light radiation: can produce visually sensitive radiation energy.

Note: There is no clear definition of the spectral range limit of visible light radiation, and different users have different understanding. The lower limit is generally defined as 380nm and 400nm, and the upper limit is defined as 760nm and 780nm.

3.22 Xenon lamp Reference fabric: dyed polyethylene fabric, used to verify the temperature conditions of the test chamber in the color fastness test. (See 32.3 and 32.6)

3.23 For other terms related to color fastness testing, please refer to AATCC International Standard terminology.

AATCC TM16-0 “Aging Test Method”

4 Safety tips
Note: These security tips are for informational purposes only. These tips are an aid to the detection procedure and do not include all tips. It is the responsibility of the user to ensure safe operation during the inspection. Consult the manufacturer for specific details, such as material safety data sheets and other manufacturer recommendations, and also comply with all OSHA standards and guidelines.

4.1 Do not use the instrument without reading and understanding the manufacturer’s operating instructions. Users are obliged to follow the operating instructions for safe use.

4.2 The test instrument has a high concentration of light source, do not directly look at the light source. The test chamber door should be closed while the instrument is in operation.

4.3 Allow the light source to cool for 30 minutes before operating on it.

4.4 When testing the instrument, turn off the switch and unplug the power at the same time. During operation, ensure that the main power display displays the instrument running.

4.5 Prolonged sun exposure to skin and eyes is very dangerous, so protective measures should be taken. Do not look directly at the sun under any circumstances.

4.6 It is necessary to perform good laboratory practices and wear safety glasses in all areas.

AATCC TM16-0 “Aging Test Method”

5 Use and Limitations
5.1 Not all materials have the same impact on the same light source and environment. The results of any test option are not representative of any other option or final application unless mathematical correction is established for a particular material or application. The enclosed carbon arc, xenon arc and fluorescent lamps are widely used in the trade as a standard for testing materials. Different test instruments offered by different vendors vary greatly in spectral distribution, air temperature, humidity sensor positioning, and test chamber size, all of which can lead to different results reported in the test. Therefore, the results obtained with different manufacturers and different parameters cannot be converted to each other unless the corresponding mathematical correction is established. There is no inter-instrument calibration method for the AATCC RA50 association.

5.2 The results for all materials tested for xenon arc lamps should fully match the results for sunlight through the glass window (see Table 2). The results are consistent with those obtained from actual sunlight and sunlight through the glass window because it is assumed that THE spectrum provided by the instrument with the filter combination is different from the average or typical spectrum through the glass window.

5.3 When using this test method, the selected test option should be equipped with light, humidity and heating effects based on historical data and experience. The test option chosen should reflect the actual conditions of the sample well.

5.4 When using this test method, a set of standard comparators with known color fastness is used to evaluate the tested samples. The AATCC Blue wool standard is widely used for this purpose.

Equipment and raw materials
6-1 AATCC blue wool color fastness to light L2 to L9

6-2 xenon arc reference fabric

AATCC Blue wool fading standard L4 for fading unit 20

AATCC Blue wool fading standard L2 of fading unit 20

6-5 xenon arc reference fabric fade standard

6-6 AATCC color difference gray sample card

6-7 Paper card –163g/m2(90 lb) per share

6-8 Raw material detection cover with transmittance close to 0, suitable for a variety of exposure degrees, such as AATCC fading unit 10, 20, 40, etc.

6-9 Blackboard thermometer

6-10 Black standard thermometer

AATCC TM16-0 “Aging Test Method”

Note: Blackboard thermometers and black standard thermometers should not be confused, where the latter is mainly used in the option 5 xenon ARC for continuous irradiation and European testing procedures. The temperature measured by two different devices under the same conditions is generally different. The black thermometer mentioned in this standard refers to the blackboard thermometer and the black standard thermometer.

Make sure that the temperature you choose is suitable for the type of black thermometer you are using

c Because the blackboard thermometer and the black standard thermometer have different temperature sensing units, options 3 and 5 specify different temperature setting points

6-11 Spectrophotometer or colorimeter

Xenon arc lamp fading device may be provided with light monitor and control system.

6-13 Sun exposure room.

6-14 Carbon arc lamp fading device.

AATCC TM16-0 “Aging Test Method”

7 Comparison criteria
The light fastness of AATCC blue wool as defined in Method 16 is preferred for all test items. However, the fading rate of AATCC blue wool color fastness to light in one test item is generally not applicable to other tests.

7-2 Reference standard applies to textile raw materials with known color difference. The reference standard for comparison needs to be jointly decided and agreed upon by both parties. The standard and specimen should be exposed at the same time. The use of standards contributes to the difference in measurement equipment and testing procedures. If the test result of the exposure standard is higher than 10% of the known standard data, the operating condition of the equipment should be effectively checked and any errors or imperfections should be corrected. Then, repeat the test.

8 Preparation of the sample
8-1 Number of Samples — In order to ensure the accuracy of testing, at least 3 identical samples of each raw material shall be tested, and standards shall be used to ensure accurate testing, unless the purchaser and the supplier agree.

Note: In practice, one test sample and one control sample are generally used for the purpose of detection. This procedure cannot be accepted in controversial cases, but it can meet the needs in routine testing.

8-2 Sample cutting and Placement — Identify each sample with a label that will not be affected by the environment during testing. When the specimen is placed on the sample rack, its surface and reference standard are at the same distance from the light source. Use a cover to avoid compression of the sample surface, especially when testing fleece fabrics. The size and shape of the sample are consistent with that of the reference standard sample. The procedures for shearing and preparing the specimens are as follows:

8-2-1 Sample Reinforcement — For all test items, place samples and standard references on white paper cards. When the placed sample is covered, a cover with a light transmittance close to 0 is used. For option C, make suitable reinforcement adjustments to the sample placed or covered on the sample shelf: for example, metal plate or solid lining.

8-2-2 Fabric — Cut at least 70.0×120.0mm(2.75×4.7in.) fabric sample in the direction parallel to the machine. The exposed area to be determined shall not be less than 30.0×30.0mm(1.2×1.2 in.). Protect the fixed samples on the sample rack of the testing instrument. Make sure that the cover on the front and back of the support is well connected to the sample, and mark the boundary between the exposed area and the non-exposed area without pressing the sample.

8-2-3 Yarn — Wrap or tie a length of yarn close to 150.0mm(6.0in.) on a white paper card sample rack. Calculate only the color difference of the yarn against the radiated energy. Wrap a yarn bundle of at least 25.0mm(1.0in.) width on the sample rack. The control sample contains the same number of shares as the exposure sample. After exposure, tie the exposed yarn together with a 20mm(0.75in.) marker or appropriate tape to ensure that the yarn is secured to the exposure rack for measurement.

AATCC TM16-0 “Aging Test Method”

9 Operating conditions of equipment
9 Preparation of test equipment

Before running the test program, check the operation of the instrument by using the following test protocol. To improve the repeatability of the test results, the instrument was installed in a room where the temperature and humidity were controlled according to the manufacturer’s requirements.

9-2 Check the calibration and maintenance of the instrument at specified intervals as required by the manufacturer.

9-3 If you can, turn off all gears and the jet part of the instrument.

9-4 Set the operating environment of the instrument according to Table 1 and the specified items. Make sure the temperature you choose is suitable for the type of black thermometer you are using. Place a white paper card and the necessary black thermometer on the sample rack. The white paper card is used to imitate the air flow in the test room during the test exposure and should not include the sample. Support the chalkboard standard thermometer unit in the sample chamber or sample holder in the same manner as the sample holder. Operate and control the test instrument according to Table 1 and further instructions of the manufacturer. Operate the instrument in this manner and adjust the test equipment to provide the desired blackboard or black standard temperature, air chamber temperature and humidity. When the external indicator is not available, the reading on the standard thermometer on the blackboard can be read through the window in the inspection room door.

9-5 Calibration using the AATCC Blue Wool standard according to steps 11.1 to 11.2.2. If the fading of L2 or L4 does not meet the requirements of the manufacturer’s calibration instructions, repeat exposure with the new L2 or L4 standard. If the fading meets the requirements of Part 11, remove the white paper card from the sample holder.

For more information on preparing and running test equipment, refer to the manufacturer’s instructions and the following:

For all carbon arc test items, use ASTM G151&G153.

9-6-2 For glass filter, use test standard ASTM G24.

For all xenon arc testing items, use ASTM G151&G155.

For applicable test items, refer to Part B of ISO 105.

Calibration, calibration and measurement of AATCC fading units
AATCC TM16-0 “Aging Test Method”

10-1 Instrument Calibration — To ensure standardization and accuracy, parts related to exposure equipment (light monitor control system, black thermometer, air chamber sensor, humidity control system, UV sensor and radiometer) need to be calibrated regularly. Wherever possible, calibrations should be made against national and international standards. The calibration schedule and procedure shall conform to the manufacturer’s instructions.

10-1-1 The correctness of the operation of the equipment shall be demonstrated by the evaluation of AATCC blue wool light fastness to exposure and AATCC fading unit 80-100. The usual exposure reference is located near the center portion of the sample holder near the sensing unit of the blackboard thermometer.

The light fastness of blue wool was calibrated by AATCC
11-1 Carbon arc detection Items 1 and 2; Xenon arc test items 3 and 4, AATCC blue wool light fastness L4 for 20±2 hours continuous exposure at specified temperature, humidity and options (see Table 2 for AATCC fading units for xenon arc lamps). After exposure, the exposed standard sample is evaluated by visual inspection or instrument. Increase OR DECREASE THE wattAGE OF THE LAMP, THE EXPOSURE TIME, or BOTH, AND EXPOSE another STANDARD SAMPLE UNTIL ITS COLOR difference meets one of the following standards.

11-1-1 Visual comparison — Color difference comparison applies standard series fading standard L4 series.

11-1-2 Instrumental determination of colour – For Class 5, AATCC blue wool colour fastness to light, equal to 1.7±0.3 CIELAB colour difference in units, determined using AATCC assessment procedure 6. AATCC blue wool color fastness to light L4 other standard grades, in accordance with the AATCC evaluation procedure 6 check color difference CIELAB units.

AATCC TM16-0 “Aging Test Method”

a 1.7±0.3 CIELAB units or AATCC gray card grade 4 color difference

b All other data were calculated and verified by continuous irradiation experiments with glass filters and xenon arc lamps.

11-2 Carbon arc detection item 1 or 2; Xenon arc test item 3 or 4, AATCC blue wool light fastness L2 continuous exposure at specified temperature, humidity and selected conditions for 20±2 hours. After exposure, the exposed standard sample is evaluated by visual inspection or instrument comparison with fading standard L2. Increase OR DECREASE THE wattAGE OF THE LAMP OR THE TIME OF EXPOSURE, OR BOTH, AND EXPOSE the REMAINING STANDARD SAMPLE UNTIL its color difference meets one of the following standards.

11-2-1 Visual comparison — Color difference comparison applies standard series fading standard L2 series.

11-2-2 Instrument color – For AATCC blue wool color fastness to light L2 standard class 8, equal to 6.88±0.70 CIELAB color difference as defined in AATCC Rating procedure 6. For other AATCC blue wool, the standard grade L4 for color fastness to light is equal to the CIELAB unit of color difference defined in AATCC Evaluation Procedure 6.

Note: Xenon arc reference fabric is forgone due to temperature sensitivity. It is more suitable for checking the consistency of the temperature of the test room.

a The following example shows how to use Table 3 to grade light fastness

AATCC TM16-0 “Aging Test Method”

The test samples were exposed to the sun at the same time as the standard L4, L5 and L6. After exposure and adjustment, the color difference displayed by the test sample is less than the color difference of L4 and L5, but greater than the color difference of L6, then the color fastness of the test sample is rated at L5-6, or apply the following example.

During the exposure process, the sample was checked continuously until the color difference was equal to the four levels on the color difference gray card. If the exposure energy is between 40 AFU and 80 AFU, the color fastness of the test sample is rated as L5-6.

Check the temperature of the test chamber with xenon arc reference fabric xenon arc lamp option
12-1 Continuously expose xenon arc reference fabric for 20±2 hours at specified temperature, humidity, and test conditions, then evaluate the exposure standard sample by one of the following methods.

12-1-1 Visual comparison — If the color difference of the exposed standard sample meets the xenon arc reference fabric fading standard, the test equipment shall be continuously exposed for 20±2 hours to maintain the correct temperature.

12-1-2 Instrument Color Determination — If the exposure standard sample is equal to 20±1.7 color difference units after continuous exposure over 20±2 hours, the test equipment provides the correct temperature.

12-2 If the exposure xenon arc reference fabric is visually or instrumtionally tested differently from the specific application in 9-1-1 or 9-1-2, after 20±2 hours of continuous exposure, it indicates that the temperature sensing unit in the test room is not calibrated or does not respond correctly, or that the test equipment needs repair. Check the accuracy of the temperature sensor against the manufacturer’s instructions and whether all functions of the device are correctly implemented. Replace the temperature sensing unit if there is a problem.

AATCC TM16-0 “Aging Test Method”

13 AATCC fading units were determined by the light fastness of AATCC blue wool
13-1 AATCC blue wool fastness to light and the application of AATCC fading units provide a common exposure standard for a variety of testing methods: daylight, carbon and xenon arc lamps. This clock period and machine time are not valid reporting methods.

13-2 Table 2 illustrates that the number of AATCC fading unit color differences is equal to 4 levels of AATCC blue wool light fastness gray color card color differences.

13-3 For the color determination of the instrument, the chromaticity data were calculated using the light source D65 CIE 1964 10° observation data. Color differences were expressed in CIELAB units given in the AATCC rating procedure 6.

Note: FOR THE monitoring OPTIONS 2 and 4 with alternating light and dark xenon ARC lamps, although multiple hours of continuous exposure were checked, it more or less occupied the detection time during the actual detection cycle due to the inclusion of the dark phase.

14 Measurement of AATCC fading units based on spectral irradiation, xenon arc detection options 3,4
14-1 For test items 3 and 4, when the xenon arc device is operated under the conditions specified in the test method, 20 AATCC fading units are generated by exposure to a measurement interval of 420nm 85KJ/m2.

Instrument exposure step options 1-5

AATCC TM16-0 “Aging Test Method”

General conditions of instrument exposure
15.1 Sample installation. Mount the sample on the test sample tray. Please ensure that the top and bottom of all materials are properly secured. Even a small deviation may lead to a difference in fading between samples. The sample holder needs to be filled, and cardboard is used when the number of samples is insufficient. If you need to alternate between dark and exposure, start with exposure.

15.2 For woven, knitted and non-woven fabrics, unless specifically requested, ensure that the normally used edges are directly exposed to light sources.

15.3 Operate the instrument on a daily basis until the selected exposure is completed. In the replacement of the filter, lamp tube is to try to avoid unnecessary delay, because such delay will lead to the deviation and error of the results. Use an appropriate recorder if possible to monitor the exposure conditions of the test chamber. If necessary, re-adjust the control to maintain the required testing conditions. The calibration of the instrument is verified during the test cycle.

16 Exposure Options 1-5 for specific radiation energies
16.1 One-step method: Expose the sample and 5, 10, 20 or more AATCC fading units at the same time until the sample has received the radiation energy required for the corresponding blue hair standard to a specific fading unit.

AATCC TM16-0 “Aging Test Method”

16.2 Two-step Method: Follow the method in 16.1 except for doubling the exposure area. After the sample has been exposed to the first required radiation energy, remove the sample from the test chamber, cover half of the area, and continue to expose 20 fading units.

16.3 The AATCC fading unit can be controlled by measuring the radiant energy at 420nm in a test chamber with a radiant energy monitor.

Note: A two-step method is recommended to complete the sun fastness test.

17 Use exposure options 1-5 for the reference sample
17.1 Expose the sample and reference sample to the required points at the same time until the reference sample has a color difference equivalent to class IV.

18 Exposure graded for color fastness
18.1 One-step method: The sample and a series of AATCC blue sample standards are placed in the test chamber at the same time to measure the fading unit required for the occurrence of class 4 color difference.

18.2 Two-step Method: Follow the method of 18.1, except double the exposure area. After the sample reaches the fourth level of gray card color difference, the sample is removed and half of the exposure area is covered until the third level of gray card change is reached.

AATCC TM16-0 “Aging Test Method”

19 Glass filter
General conditions for glass filter

19-1 Install the AATCC blue wool fastness to light and the sample on cardboard, covering half of the standard with an opaque cover.

19-2 Expose the blue wool standard and the sample under the same conditions, ensuring that the exposed side of the blue wool standard and the sample is covered at least 75.0mm(3.0 in.) under the glass plate and at least 150.0mm(6.0 in.) from the edge of the glass frame. In order to meet the required exposure conditions, the back of the exposure room can be changed according to the following:

Standards and samples were kept exposed 24 hours a day and moved only during testing.

19-3 Monitor the temperature and humidity near the testing room.

20 A specific amount of radiant energy under the glass filter exposure
20-1 Application of AATCC blue wool for light fastness-Prepare reference materials and specimens to be exposed as described in 19-1 and test them simultaneously behind glass under the same conditions as described in 19-2. The effect of daylight was monitored and color differences were recorded by moving samples from the test rack frequently. Continue exposure until the difference in color between the exposed and unexposed portions of the standard is described in Section 24. Stop detection when a specific AATCC fading unit is reached after exposure, and select the appropriate standard to obtain the end point. Standard as a regulation between class L2 and Class L9, or continuous exposure with the same regulation to a given end point; That is, the specified area is exposed to two L2 standards up to 10 fading units, or to one L3 standard up to 10 fading units.

AATCC TM16-0 “Aging Test Method”

20-1-1 Remove the sample from the exposure when the desired AATCC fade unit is reached and the equivalent of the result is calculated. For MOST EXPOSURE LEVELS, WHICH ARE 5 or 20 FADING UNITS, an exposure SAMPLE is partially COVERED AND measured at standard time intervals. The result is a sample with original cover, unexposed parts and different parts. Each part of the sample, represented as a certain exposed area, can be assessed relative to the covered control area or the unexposed part of the sample.

20-2 Application of Radiation Monitor — Prepare reference and specimen to be exposed as described in 19-1 and test simultaneously under the same conditions behind glass as described in 19-2.

Note: The well-known property of AATCC blue wool fastness to light is very useful when abnormal conditions occur during testing.

20-2-1 Record any, or a comprehensive combination of, radiometer illumination wideband pass or narrowband pass, exposed to the same conditions as the sample.

20-2-2 Remove the reference and sample from the exposure when the expected radiation energy is measured with the radiometer. For most levels of exposure, a partially covered sample can be determined at certain time intervals.

Reference sample for sun exposure
21-1 Replace the reference sample with AATCC blue wool for light fastness as described in 20-1 and 20-2.

AATCC TM16-0 “Aging Test Method”

22 Level of sunlight exposure
22-1 Level 1 Test method — Simultaneously exposed specimens and a set of AATCC blue wool for light fastness as described in 19-1 and 19-2, or AATCC fade units required to test specimens, equal to level 4 of gray color difference.

22-2 Secondary TEST Method — as described in 22-1, except that the sample is twice the size of the test area. When the color difference of the sample reaches level 4 of the gray sample card after exposure, remove the sample from the test rack and cover half of the exposed area. Continue exposure until the color difference of the sample reaches level 3 of the gray sample card.

23 Determination of the results

23 Balance
23-1 Remove the sample and standard from the exposure after the exposure test. The standard condition for testing is to balance the sample in a dark room for at least 4 hours prior to assessment under the conditions specified in ASTM D1776 [65±2%RH and 21±1 ° C (70±2 ° F)].

Evaluation of color difference
24-1 Compare the exposed part of the sample with the covered control part or the unexposed part, and classify the insolation of the sample according to the instructions of the raw material or the purchase order. The test exposure level is required to be higher than one.

24-2 Use AATCC gray sample cards or colorimetric tests to indicate color changes at specific exposure levels, whether or not AATCC fade units are used, radiant energy is in kilojoules, or compared to standards.

24-3 Determination of total color difference (△ECIELAB), brightness change, chromaticity change, and hue change (△L*,△C*,△H*) using a meter that provides CIE 1976 equation data using D65 light source and 10° observer data. Suitable for instrumentation using diffuse geometry, including measuring devices with special reflective components. (Refer to AATCC Assessment Procedure 6)

25 Approval of reference samples based on the same exposure conditions
25-1 Evaluate the color change of the raw material specified in Section 24 as consistent with the reference sample.

AATCC TM16-0 “Aging Test Method”

25-2 Evaluate the insolation of raw materials according to the following methods:

25-2-1 meets the REQUIREMENTS —- when the color change of the reference sample is equal to level 4 of the AATCC gray sample card. The color difference displayed by the sample is less than or equal to that of the reference sample with the same exposure.

25-2-2 does not meet the requirements —- When the color change of the reference sample is equal to level 4 of the AATCC gray sample card, the color difference displayed by the sample is greater than that of the reference sample with the same exposure.

Classification according to AATCC blue wool fastness to light
26-1 Level 1 Exposure — The insolation rating of raw materials shall pass:

(a) Comparison of color difference between the sample and AATCC blue wool under the same conditions (see Table 3), or

(b) AATCC fading unit of color difference according to AATCC gray sample card Class 4 standard sample.

26-2 Secondary Exposure — The insolation rating of raw materials shall pass:

(c) AATCC fading unit of color difference between class 4 and Class 3 standard samples according to AATCC gray sample card (see Table 3).

26-2-1 Two levels are marked: level 3 at the front and level 4 in parentheses at the back. For example, level L5(4) represents level L5 in level 3 and level L4 in level 4. When only one level number is annotated, it indicates that the AATCC fading unit is 4 levels.

AATCC TM16-0 “Aging Test Method”

AATCC blue wool classification of light fastness class L7 or above
27-1 Use Table 4 to classify AATCC blue wool for light fastness above grade L7 according to the total amount of continuous L7 standard color difference conforming to Grade 4 of gray sample card during exposure. Test samples shall conform to Grade 4 color difference and Table 4.

Table 4 — Light fastness classification of AATCC blue wool with grade L7 or above

Q-SUN xenon lamp tester conforms to AATCC TM16 test model and machine setup method