StacksVerified U.S. regulatory reference

40 CFR Part 53, Table E-2

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov
CharacteristicSpectral Region
UltravioletVisible | Infrared
Bandwidth (µm)0.28 to 0.32 0.32 to 0.40 | 0.40 to 0.78 | 0.78 to 3.00
Irradiance (W/m2)5 56 | 450 to 550 | 439
Allowed Tolerance±35% ±25% | ±10% | ±10%

[62 FR 38799, July 18, 1997; 63 FR 7714, Feb. 17, 1998]