LVTO with inoperative RVR measument units
If you are doing a CAT 2/3 approach the legislation ( by provision of the table titled “Failed or Downgraded Equipment - Effect on landing minimum operations ” allows you to use a runway with RVR measurement units that have failed.
However in the case of an Low visibility take off ( especially one under 150m) I have yet to spot such provision . The only LVTO statements that we have to work with are :
1. “The reported RVR/VIS value representative of the initial part of the take-off run can be replaced by pilot assessment.”
2. The required RVR value is achieved for all of the relevant RVR reporting points;
So from what I can infer if the initial RVR Unit is inoperative , the crew could entered the runway and make their own assessment. However if their take off performance was such that their ASDR was using the 2nd or the 3rd part of the runway , if any of those RVR measument units where to fail they would not be allowed to depart .
Please elaborate if there is provision for something different.