321J.5  Preliminary screening test.
  1.  When a peace officer has reasonable grounds to believe that either of the following have occurred, the peace officer may request that the operator provide a sample of the operator’s breath for a preliminary screening test using a device approved by the commissioner of public safety for that purpose:
  a.  A motor vehicle operator may be violating or has violated section 321J.2 or 321J.2A.
  b.  The operator has been involved in a motor vehicle collision resulting in injury or death.
  2.  The results of this preliminary screening test may be used for the purpose of deciding whether an arrest should be made or whether to request a chemical test authorized in this chapter, but shall not be used in any court action except to prove that a chemical test was properly requested of a person pursuant to this chapter.
86 Acts, ch 1220, §5; 95 Acts, ch 48, §12