photoelectric tube

18 LETTERS · STARTS WITH P

photoelectric tube is a valid 18-letter word worth 28 points in Scrabble and 33 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

P3H4O1T1O1E1L1E1C3T1R1I1C3T1U1B3E1

3 + 4 + 1 + 1 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 3 + 0 + 1 + 1 + 3 + 1 =28 PTS

DOUBLE WORD → 56TRIPLE WORD → 84

MEANING

What does photoelectric tube mean?