Table 1.

Transmittance for sun glare filters for general use of NBR15111(2013) [10]

	Requirements
	Ultraviolet spectral range		Visible spectral range
Filter category
	Maximum value of spectral transmittance τ F ( λ )	Maximum value of solar UVA transmittance τ SUVA ( λ )	Range of luminous transmittance (380-780 nm) τ V
	280-315 nm	> 315-400 nm	From over %	To %
0	0.1 - τV	τV	80.0	100
1			43.0	80.0
2			18.0	43.0
3		0.5 - τV	8.0	18.0
4			3.0	8.0