WEAR AMOUNT MEASURING INSTRUMENT

PROBLEM TO BE SOLVED: To provide a wear amount measuring instrument for easily measuring, by a simple structure, the wear amount of a member immersed in water which wears. SOLUTION: On sliders 13a or 14a of rotary rings 13 or stationary rings 14 of a mechanical seal 8, RFID tags are mounted leaving circumferential or axial spaces between them while RFID tag readers 22A and 22B are disposed in the vicinity of the RFID tags mounted on the sliders 14a of the stationary rings 14. A display 25 of this wear amount measuring instrument is for determining that the sliders 14a of the stationary rings 14 have worn as far as their parts mounted with RFID tags when communication in water has become impossible between the tag readers 22A and 22B and the RFID tags mounted on the sliders 14a of the stationary rings 14. Further, RFID tags uncoupled from the sliders 13a and 14a are detected by an RFID tag reader provided at some midpoint in the route of purge water discharge piping 35 or leak water piping 36 to determine that wear has developed as far as a position where the reader is mounted. COPYRIGHT: (C)2010,JPO&INPIT