PHOTO THRESHOLD AWARENESS FUNCTION
A class with identifier
http://staging4.data.posccaesar.org/iso/15926-4/rdl/RDS9999251
| Definition | A <PHOTO THRESHOLD AWARENESS FUNCTION> is a <Property> that is a measure of the the ability of the human eye to detect a light that results in a 1 degree radial angle at the eye with a given <DURATION> (temporal summation) | 
| ISO number | 18783 | 
| RDS number | RDS9999251 | 
| Source | ISO 15926 CR6 PROPERTY AND STATUS (VTver1) |