A professional who operates assembled typewriters to test their performances. Responsibilities include:

• Types characters in prescribed sequence on sample sheet to evaluate functioning of parts, such as shift, ribbon feed, key levers, tabulator, carriage, and spacebar.
• Indicates on prepared form condition of machine, such as excessively noisy, binding parts, misaligned type, and jammed backspace.
• Sends report and defective machines to typewriter aligner for repair or adjustment.
• Repeats tests on adjusted or repaired machines to verify corrections.