Translation help Please

[Long Shot]

Found these markings and was wondering what they say? Appreciate any help provided.

[Nick Komiya]

The phrasing makes it sound Chinese rather than Japanese. 試管 is Chinese for test tube, which in Japanese is expressed as 試験管, requiring one more Kanji. 司 means to administer. It may mean a test tube containing the control sample, but still not quite Japanese.

[Nick Komiya]

Just was supplied a photo that shows things in the right context. The three characters were not one word at all, but 3 different switch positions for a control switch, no wonder it was not Japanese phraseology anymore. 司 might be command or commander, 試 is test position and 管 might be management. Longshot wanted to know whether the last could refer to a torpedo tube. That is possible but a long shot. 魚雷菅 is torpedo tube and one would take the first 2 or the second kanji normally as abbreviation. It looks like an onboard comm system switch of some sort.