scanner

(noun) someone who scans verse to determine the number and prosodic value of the syllables.

(noun) an electronic device that generates a digital representation of an image for data input to a computer. Synonyms: digital scanner, image scanner.

(noun) a radar dish that rotates or oscillates in order to scan a broad area.

(noun) a radio receiver that moves automatically across some selected range of frequencies looking for some signal or condition. Synonyms: electronic scanner. Example: "They used scanners to monitor police radio channels."