Originally Posted by
BizJetJock
If the first section RVR is inop, then you can count the visible lights to assess the RVR yourself for the first section only.
Hope that helps!
Runway Visual Range (RVR) is the range over which the pilot of an aircraft on the centre line of a runway can see the runway surface markings or the lights delineating the runway or identifying its centre line. (ICAO Annex 6: Operation of Aircraft)
RVR used to be assessed manually at given time intervals by a vehicle on the runway with a viewing platform at a prescribed (pilots eye) height. What is generally reported these days is IRVR which is measured between sensors ADJACENT to the runway, not on it. With either system the best person to judge the actual current RVR in the touchdown zone is the pilot. Therefore I believe that pilot observation overrides reported TDZ RVR (up or down).