The ECCs used in the test method will ultimately be exposed (Test Method E2141) to solar radiation and deployed to control the amount of radiation by absorption and reflection and thus, limit the solar heat gain and amount of solar radiation that is transmitted into the building.

4.2 The test method referenced herein is a laboratory test conducted under specified conditions. This test method is intended for use in assessing the changes in uniformity of an ECC on vision glass and subjected to a series of tests for assessing the durability of the coating or the IGU unit, or both.

4.3 The useful life of IGUs with an absorptive ECC may depend on their ability to maintain an acceptable uniformity when used in an IGU for buildings applications. As described in Section 1. (See Appendix X1, X1.4 and X1.5), this test method is intended to provide a means for measuring the uniformity of an absorptive electrochromic coating (ECC) on a glazing surface (including when sealed in an insulating glass unit).

Effects of Test Procedures-Data generated using this test method may be used to evaluate and compare the effects of subjecting ECCs in IGUs to the accelerated weathering procedures described in Test Methods E2141, E2240, or E2241. This test method requires the measurement of uniformity as a basis for evaluating changes in one of several performance parameters.

Changes in the uniformity of the test specimens may vary from none to significant. Some physical changes in the specimens may be visible when there are no apparent changes in the performance. Similarly, performance changes may occur with no visible changes in the specimens.

All conditions of measurement in this test method must be described in the report so that an assessment of their significance can be made.

Sequencing-If this test method is performed as part of a combined sequence with other measurements of the ECC perfomance (see 8.2) and visual inspection (see 8.3 in Test Methods E2141, E2240, or E2241) determined at the end of one of the test methods, the result may be used as the initial uniformity measurement for the next test; duplication of these uniformity measurements is not necessary unless so specified.