D.L.S. performs the entire environmental suite of tests found in MIL-STD 810 G, method 506.6, procedures 1, 2, and 3.
Included are rain and blowing rain, exaggerated, and drip. These tests are often performed as part of an environmental testing program that includes other climatic or mechanical tests found in MIL-STD 810 G, in addition to MIL-STD 461 EMI related tests.
More information can be found at: http://www.dlsemc.com/environmental/env-mil-810/rain.htm.