Section 28-304.6.1. Inspection and testing entities

The required periodic
  inspections shall be made by the department, except that one  inspection
  and  test  for  elevators  and  escalators shall be made between January
  first and December thirty-first of each year on behalf of the  owner  by
  an  approved  agency  in  accordance  with  this  code  and  with  rules
  promulgated  by  the  commissioner.  Required  inspections   and   tests
  performed  on  behalf  of  the  owner  shall be performed by an approved
  agency in accordance with rules of the department and  witnessed  by  an
  approved  agency  not  affiliated  with the one performing the test. The
  department shall be notified at least  10  days  prior  to  the  owner's
  periodic inspection and testing pursuant to rule of the department.