rectifier instrument

20 LETTERS · STARTS WITH R

rectifier instrument is a valid 20-letter word worth 26 points in Scrabble and 31 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

R1E1C3T1I1F4I1E1R1I1N1S1T1R1U1M3E1N1T1

1 + 1 + 3 + 1 + 1 + 4 + 1 + 1 + 1 + 0 + 1 + 1 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 =26 PTS

DOUBLE WORD → 52TRIPLE WORD → 78

MEANING

What does rectifier instrument mean?