Check detector seals, and replace as necessary.

检查检测器密封垫，如有必要就替换。

youdao

Check detector seals, and replace as necessary. Clean or replace detector jets as necessary.

检查检测器密封垫，如有必要就替换。如有必要清洗或替换检测器喷嘴。

youdao

Check detector seals, and replace as necessary. Clean or replace detector jets as necessary.

检查检测器密封垫，如有必要就替换。如有必要。

youdao

The Letter Logger can be programmed to check its position every few minutes, over longer intervals, or only when a built-in motion detector senses movement, says Jude Daggett, of TrackingTheWorld.

ECONOMIST: Monitor