Romulan tricorder

The tricorder was used by Romulans from 2368 to 2371.

2368 Version
This tricorder was used by Romulan crewmembers aboard a damaged Romulan science vessel in 2368. 
 * This was not explicitly stated to be a tricorder.

Sub-commander N'Vek used a tricorder to scan Deanna Troi for traces of a sedative. 

2371 Version
This tricorder was very similar to that of the Federation. It was much larger, but still featured touch interface control surfaces. A tricorder was recovered from the Amargosa observatory in 2371 and allowed the USS Enterprise (NCC-1701-D) crew to learn that the Romulans had been searching for trilithium stolen by the Duras sisters for use in Dr. Tolian Soran's trilithium weapons. 
 * This tricorder was designed by John Eaves.